> If I walk into a shop, the shopkeeper doesn't know if something in the window caught my eye, if my friend recommended the helpful staff, if I saw the advert t

> If I walk into a shop, the shopkeeper doesn't know if something in the window caught my eye, if my friend recommended the helpful staff, if I saw the advert they placed on a billboard, or if I just came in because it's raining. A lot of places will attach unique discount codes to advertisements to get an idea on where you came from. For example, on a TV commercial it might say use promo code COOL123 to save 10% or if you saw that billboard it might say to use NICE123 instead. Then there's radio, newspapers and so on each with their own unique code that offer the same 10% discount. And since a discount is applied chances are you'll use it because not too many folks would purposely avoid the discount to hide where you discovered the shopkeeper from. You often see this being done online too, but there's also things like UTM tags or unique URLs that let you do the same thing without discount codes. It's not to make more money as a shopkeeper (avoiding the discount), it's just easier to set up. Using a UTM tag is a matter of creating a link with a few query parameters. Creating a specific discount code or a unique URL for a specific promotion takes a bit of extra leg work. I'm not sure where I stand on the movement to remove all forms of referral tracking. Both referral headers and UTM tags can be spoofed or removed through extensions so using them as any type of source of truth was a bad idea anyways. However, as someone who sells digital products I like knowing which specific video or blog post helped someone discover some of my paid content. But at the same time, the end game is really "is the needle moving forward?" so the specifics kind of don't matter. But in the short term while you're figuring things out, the extra info does help you focus on where to spend your time. Not just for more profit, but to provide better and more free content because it's what folks want.