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The Story behind ASINs – Amazon Standard Identification Numbers (2021)

158 points by sgraaf 4y ago

aftbit 4y ago
Some products come from AFN/FBA with an ASIN-formatted number on a barcode on the product bag, but which starts with "X" instead of "B". I believe this to be some kind of inventory tracking code that relates the product to the vendor who shipped it into the Amazon fulfillment network. At the rate of 100B ASINs allocated per year, Rebecca may be disappointed to know that in only 967 years, Amazon will begin to collide between ASINs and whatever these numbers are. Honestly I expect they'll hit some big problems when they first allocate ASINs beyond Bxxxxxxxx as I'm sure a lot of software has begun to expect all ASINs to either be an ISBN or start with "B".
- emodendroket 4y ago
  That may well be, but the beauty of a distributed system where each service has a discrete owner is that that’s their problem.
- TMWNN 4y ago
  >Some products come from AFN/FBA with an ASIN-formatted number on a barcode on the product bag, but which starts with "X" instead of "B". I believe this to be some kind of inventory tracking code that relates the product to the vendor who shipped it into the Amazon fulfillment network. Correct. It is an FNSKU (Fulfillment Network SKU), which is both product- and seller-specific. Amazon listing for item with ASIN B1234567: * Seller 1 sells on the listing. His inventory of B1234567 is assigned FNSKU X8675409. When he sends inventory to Amazon, each unit must have a sticker with X8675409 covering the UPC code, or the seller can pay a fee for Amazon to affix the sticker. * Seller 2 sells on the listing. His inventory of B1234567 is assigned FNSKU X4894608. When he sends inventory to Amazon, each unit must have a sticker with X4894608 covering the UPC code, or the seller can pay a fee for Amazon to affix the sticker. For most listings, the seller can choose to use the UPC code instead of Amazon assigning an FNSKU. Called "commingling", this is unwise because there is no way for Amazon to distinguish between its own inventory, your genuine inventory, and another seller's counterfeits. Amazon says that its inventory procedures still differentiate between sellers, but a) no one believes this and b) all the stated procedures would do in a case of, say, Seller 2's counterfeit item being shipped when Seller 1 makes a sale would be to potentially identify that Seller 2 is the source of the counterfeit, as opposed to avoiding shipping it in the first place.
WorldMaker 4y ago
I bet there are some interesting stories from the groups that tried to use the A-prefixed ASINs.
oaththrowaway 4y ago
Years ago I spent a lot of time trying to figure out how to get a Kindle to "Whispersync" sideloaded books. Eventually I figured out it was as simple as having an ASIN included in the books metadata (Calibre does this automatically now, but it was fun figuring it out manually with Python scripts). Originally I thought the ASIN had to be valid, but eventually realized it didn't even matter, just had to match the pattern.
- RockRobotRock 4y ago
  Wow, TIL. So you're saying you can get the audiobook legit through Audible and use a downloaded EPUB and it will still work if the ASIN is in the metadata? This is definitely worth a blog post or something at least.
  - innocenat 4y ago
    No. A USB side-loaded book in AZW3 or KFX format with embedded ASIN, and tagged EBOK, is treated as Amazon books. Everything sent via Send to Kindle is tagged PDOC so they behave differently. Normally, books sent via USB can't use Whispersync to sync reading position between different devices. OP is saying that if you embed ASIN into the book (can just be a random ASIN) and sideload the same books to multiple device, they will sync, too.
    - RockRobotRock 4y ago
      Is there any way to do this with the Kindle app instead of a physical Kindle?
password11 4y ago
> I objected to subdividing and having different parts of the string mean different things because it would substantially reduce the addressable space, and limit the number of items that could be moved through Amazon before having to go back and do this re-keying exercise again, with an even bigger code base. The people who wanted “special” ASINs were pretty persistent, though, so I threw them a bone: they could have all the ASINs that started with the letter A, and I would start the counter for ASINs at B000000000. Finally, this proposal had to get past...
philwelch 4y ago
Here’s some ASIN trivia from my time at Amazon in the early 10’s. At least at that time, there was exactly one inventory item at Amazon that could change ASINs during its lifetime: Amazon Fresh used different ASINs for green bananas and yellow bananas.
- seniorsassycat 4y ago
  Is it actually a mutate or do you write off greens and add new yellows?
  - philwelch 4y ago
    I heard this second hand; I don’t actually know how the inventory for Fresh worked at the time.
  - dylan604 4y ago
    If you're Enron, you count both as being in the inventory
  - hef19898 4y ago
    No idea hoe Amazon did it, but I suspect a inventory transfer from green to yellow. That is properly tracked and accounted. You never use inventory adjustments to move inventory, as tose are literally shooting inventory into the aether (negative adjustments) and creating inventory out of thin air (positive ones), resulting in zero inventory tranparency or traceability.
- eyelidlessness 4y ago
  I don’t know if I’m more surprised that Amazon Fresh existed in the early 10s or that Amazon Fresh sold green bananas in that timeframe.
  - philwelch 4y ago
    Fresh dates back to 07, actually, though it was delivery-based and almost entirely in Seattle originally. They have gone through a few pivots since then.
roxgib 4y ago
> Unfortunately — and Shel was well aware of this very quickly, but of course by that time, it was too late — ISBNs are terribly abused in the United States. The company that issues ISBNs, Bowker, charges a lot of money for ISBNs (from the perspective of small publishers, anyway), and publishers don’t necessarily read all the rules. Small publishers were re-using ISBNs, and they also took their range of ISBNs and numbered through the entire range, rather than respecting the rule that the final character is actually a checksum, and you can only iterate through some of the digits. (It’s actually worse than just not using the last digit, but I’m not getting into that here.) If there's a single company issuing them how are there companies using ones with invalid checksums?
- emodendroket 4y ago
  It sounds like you buy a range of numbers and publishers use invalid ones in that range rather than pony up for more of them.
- tharkun__ 4y ago
  Because you get issued a range and you actually do whatever you want within that range. Like IP addresses. What you do within that range is up to up, you don't actually have to ask the authority for every single number within the range. As a simplification: If you get the number from 100 to 200 to assign to your books but the last digit is a check digit, you didn't get 100 numbers to choose from. You got to choose from: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and the third number is the check digit, which is computed from the other numbers. Just with ISBNs (and other numbering schemes) the numbers are larger of course. Going back to the IP address analogy: if you are issued 11.0.0.0/8, you can use anything from 11.0.0.1 to 11.255.255.255 but you don't have to start with 11.0.0.1 and you don't have to treat it as one big /8 either. You can subdivide it into multiple /28s for example. The only difference here is that with ISBNs (or anything else that has a check digit) is that the last digit is not freely usable. It's just a check digit. It's not really part of the range so to speak. It's like you subdividing your /8 into lots of /28s but ignoring the fact that the network address on the /28s is actually the network address and having one of the computers in your network use it as their actual IP address. That's obviously gonna wreak some havoc because some of your network thinks it's a network address for one of the /28s and some others think it's an individual computer.
layer8 4y ago
(2021)
- dang 4y ago
  Added. Thanks!
greenie_beans 4y ago
wow this blog might be a gold mine for me rn? (also i feel like an idiot for trying to make another bookstore ecommerce platform (wip))
layer8 4y ago
> It’s actually worse than just not using the last digit, but I’m not getting into that here. Clearly, using only nine characters would have been asinine.
dark-star 4y ago
I always wondered why ASINs start with B..... Anyone know what the A.... ASINs that were mentioned in the article are/were used for?
- hakanensari 4y ago
  They appear to have never been used!
neilv 4y ago
In addition to the other associations of the name "ASIN", there was also the Pet Shop Boys hit pop song "It's A Sin", several years earlier: https://www.youtube.com/watch?v=dRHetRTOD1Q&t=1m https://www.youtube.com/watch?v=dRHetRTOD1Q&t=1m
- neilv 4y ago
  For everything I want to sell No matter book or bathtub gel There's one key thing in S-Q-L I need, I need, I need, its ASIN
0x08 4y ago
TCIN - Target.com Item Number source: https://www.salsify.com/blog/target-set-a-june-30-image-deadline-what-can-you-do-to-meet-it https://www.salsify.com/blog/target-set-a-june-30-image-dead... This is to differentiate it from their in store operations: DPCI - DePartment Class Item source: https://frugalfinders.com/target-dpci-number/ https://frugalfinders.com/target-dpci-number/
kwanbix 4y ago
The problem with ASINs is that they are not unique within amazon marketplaces. So B0000001 could be a toy in USA and a Book in Germany.
- warp 4y ago
  In general they seem to match (I just checked a random product from amazon.com, B08VD5JZJD), and get the same product when opening /dp/B08VD5JZJD on german amazon, france, japan, spain and UK. Has this perhaps changed over time, are there older ASINs which are different between regions, but new ones refer to the same product everywhere?
  - tuxlifan 4y ago
    Anecdotal, about 15 years ago I had good success with using USA site ASINs on a European site but about 5 years ago I only got "not found" results so I stopped trying and do the "try typing in the name and hope for the best"-dance if I don't skip amazon directly and search on meta-portals instead (in particular for IT devices geizhals.eu has a very extensive filter system so it's easier to also search for alternatives in one go). I don't remember which categories the items belonged to though or if there might have been some "market region" restrictions/scarcities placed by the sellers.

158 points by sgraaf 4y ago

Some products come from AFN/FBA with an ASIN-formatted number on a barcode on the product bag, but which starts with "X" instead of "B". I believe this to be some kind of inventory tracking code that relates the product to the vendor who shipped it into the Amazon fulfillment network. At the rate of 100B ASINs allocated per year, Rebecca may be disappointed to know that in only 967 years, Amazon will begin to collide between ASINs and whatever these numbers are. Honestly I expect they'll hit some big problems when they first allocate ASINs beyond Bxxxxxxxx as I'm sure a lot of software has begun to expect all ASINs to either be an ISBN or start with "B".

emodendroket 4y ago
That may well be, but the beauty of a distributed system where each service has a discrete owner is that that’s their problem.
TMWNN 4y ago
>Some products come from AFN/FBA with an ASIN-formatted number on a barcode on the product bag, but which starts with "X" instead of "B". I believe this to be some kind of inventory tracking code that relates the product to the vendor who shipped it into the Amazon fulfillment network. Correct. It is an FNSKU (Fulfillment Network SKU), which is both product- and seller-specific. Amazon listing for item with ASIN B1234567: * Seller 1 sells on the listing. His inventory of B1234567 is assigned FNSKU X8675409. When he sends inventory to Amazon, each unit must have a sticker with X8675409 covering the UPC code, or the seller can pay a fee for Amazon to affix the sticker. * Seller 2 sells on the listing. His inventory of B1234567 is assigned FNSKU X4894608. When he sends inventory to Amazon, each unit must have a sticker with X4894608 covering the UPC code, or the seller can pay a fee for Amazon to affix the sticker. For most listings, the seller can choose to use the UPC code instead of Amazon assigning an FNSKU. Called "commingling", this is unwise because there is no way for Amazon to distinguish between its own inventory, your genuine inventory, and another seller's counterfeits. Amazon says that its inventory procedures still differentiate between sellers, but a) no one believes this and b) all the stated procedures would do in a case of, say, Seller 2's counterfeit item being shipped when Seller 1 makes a sale would be to potentially identify that Seller 2 is the source of the counterfeit, as opposed to avoiding shipping it in the first place.

WorldMaker 4y ago

I bet there are some interesting stories from the groups that tried to use the A-prefixed ASINs.

oaththrowaway 4y ago

Years ago I spent a lot of time trying to figure out how to get a Kindle to "Whispersync" sideloaded books. Eventually I figured out it was as simple as having an ASIN included in the books metadata (Calibre does this automatically now, but it was fun figuring it out manually with Python scripts). Originally I thought the ASIN had to be valid, but eventually realized it didn't even matter, just had to match the pattern.

RockRobotRock 4y ago
Wow, TIL. So you're saying you can get the audiobook legit through Audible and use a downloaded EPUB and it will still work if the ASIN is in the metadata? This is definitely worth a blog post or something at least.
- innocenat 4y ago
  No. A USB side-loaded book in AZW3 or KFX format with embedded ASIN, and tagged EBOK, is treated as Amazon books. Everything sent via Send to Kindle is tagged PDOC so they behave differently. Normally, books sent via USB can't use Whispersync to sync reading position between different devices. OP is saying that if you embed ASIN into the book (can just be a random ASIN) and sideload the same books to multiple device, they will sync, too.
  - RockRobotRock 4y ago
    Is there any way to do this with the Kindle app instead of a physical Kindle?

password11 4y ago

> I objected to subdividing and having different parts of the string mean different things because it would substantially reduce the addressable space, and limit the number of items that could be moved through Amazon before having to go back and do this re-keying exercise again, with an even bigger code base. The people who wanted “special” ASINs were pretty persistent, though, so I threw them a bone: they could have all the ASINs that started with the letter A, and I would start the counter for ASINs at B000000000. Finally, this proposal had to get past...

philwelch 4y ago

Here’s some ASIN trivia from my time at Amazon in the early 10’s. At least at that time, there was exactly one inventory item at Amazon that could change ASINs during its lifetime: Amazon Fresh used different ASINs for green bananas and yellow bananas.

seniorsassycat 4y ago
Is it actually a mutate or do you write off greens and add new yellows?
- philwelch 4y ago
  I heard this second hand; I don’t actually know how the inventory for Fresh worked at the time.
- dylan604 4y ago
  If you're Enron, you count both as being in the inventory
- hef19898 4y ago
  No idea hoe Amazon did it, but I suspect a inventory transfer from green to yellow. That is properly tracked and accounted. You never use inventory adjustments to move inventory, as tose are literally shooting inventory into the aether (negative adjustments) and creating inventory out of thin air (positive ones), resulting in zero inventory tranparency or traceability.
eyelidlessness 4y ago
I don’t know if I’m more surprised that Amazon Fresh existed in the early 10s or that Amazon Fresh sold green bananas in that timeframe.
- philwelch 4y ago
  Fresh dates back to 07, actually, though it was delivery-based and almost entirely in Seattle originally. They have gone through a few pivots since then.

roxgib 4y ago

> Unfortunately — and Shel was well aware of this very quickly, but of course by that time, it was too late — ISBNs are terribly abused in the United States. The company that issues ISBNs, Bowker, charges a lot of money for ISBNs (from the perspective of small publishers, anyway), and publishers don’t necessarily read all the rules. Small publishers were re-using ISBNs, and they also took their range of ISBNs and numbered through the entire range, rather than respecting the rule that the final character is actually a checksum, and you can only iterate through some of the digits. (It’s actually worse than just not using the last digit, but I’m not getting into that here.) If there's a single company issuing them how are there companies using ones with invalid checksums?

emodendroket 4y ago
It sounds like you buy a range of numbers and publishers use invalid ones in that range rather than pony up for more of them.
tharkun__ 4y ago
Because you get issued a range and you actually do whatever you want within that range. Like IP addresses. What you do within that range is up to up, you don't actually have to ask the authority for every single number within the range. As a simplification: If you get the number from 100 to 200 to assign to your books but the last digit is a check digit, you didn't get 100 numbers to choose from. You got to choose from: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and the third number is the check digit, which is computed from the other numbers. Just with ISBNs (and other numbering schemes) the numbers are larger of course. Going back to the IP address analogy: if you are issued 11.0.0.0/8, you can use anything from 11.0.0.1 to 11.255.255.255 but you don't have to start with 11.0.0.1 and you don't have to treat it as one big /8 either. You can subdivide it into multiple /28s for example. The only difference here is that with ISBNs (or anything else that has a check digit) is that the last digit is not freely usable. It's just a check digit. It's not really part of the range so to speak. It's like you subdividing your /8 into lots of /28s but ignoring the fact that the network address on the /28s is actually the network address and having one of the computers in your network use it as their actual IP address. That's obviously gonna wreak some havoc because some of your network thinks it's a network address for one of the /28s and some others think it's an individual computer.

layer8 4y ago

(2021)

dang 4y ago
Added. Thanks!

greenie_beans 4y ago

wow this blog might be a gold mine for me rn? (also i feel like an idiot for trying to make another bookstore ecommerce platform (wip))

layer8 4y ago

> It’s actually worse than just not using the last digit, but I’m not getting into that here. Clearly, using only nine characters would have been asinine.

dark-star 4y ago

I always wondered why ASINs start with B..... Anyone know what the A.... ASINs that were mentioned in the article are/were used for?

hakanensari 4y ago
They appear to have never been used!

neilv 4y ago

In addition to the other associations of the name "ASIN", there was also the Pet Shop Boys hit pop song "It's A Sin", several years earlier: https://www.youtube.com/watch?v=dRHetRTOD1Q&t=1m https://www.youtube.com/watch?v=dRHetRTOD1Q&t=1m

neilv 4y ago
For everything I want to sell No matter book or bathtub gel There's one key thing in S-Q-L I need, I need, I need, its ASIN

0x08 4y ago

TCIN - Target.com Item Number source: https://www.salsify.com/blog/target-set-a-june-30-image-deadline-what-can-you-do-to-meet-it https://www.salsify.com/blog/target-set-a-june-30-image-dead... This is to differentiate it from their in store operations: DPCI - DePartment Class Item source: https://frugalfinders.com/target-dpci-number/ https://frugalfinders.com/target-dpci-number/

kwanbix 4y ago

The problem with ASINs is that they are not unique within amazon marketplaces. So B0000001 could be a toy in USA and a Book in Germany.

warp 4y ago
In general they seem to match (I just checked a random product from amazon.com, B08VD5JZJD), and get the same product when opening /dp/B08VD5JZJD on german amazon, france, japan, spain and UK. Has this perhaps changed over time, are there older ASINs which are different between regions, but new ones refer to the same product everywhere?
- tuxlifan 4y ago
  Anecdotal, about 15 years ago I had good success with using USA site ASINs on a European site but about 5 years ago I only got "not found" results so I stopped trying and do the "try typing in the name and hope for the best"-dance if I don't skip amazon directly and search on meta-portals instead (in particular for IT devices geizhals.eu has a very extensive filter system so it's easier to also search for alternatives in one go). I don't remember which categories the items belonged to though or if there might have been some "market region" restrictions/scarcities placed by the sellers.