I agree... never meant to imply that Facebook had fewer hits/etc than a banking site in raw numbers, just that the ratio of DB reads (not considered a transacti

I agree... never meant to imply that Facebook had fewer hits/etc than a banking site in raw numbers, just that the ratio of DB reads (not considered a transaction, very easy to cache, etc) to DB writes, makes the site much more read-only than write-only. Facebook has the ability to do a TON of edge caching, with very few (relatively speaking) operations having to go to the database to perform an actual write operation. It's the DB writes that really kill performance and limit your caching strategies and gains.