From what I know, it started a few years ago; but not all big stores had the equipment in place to send it (the cc processors give them a discount for sending the line-item level 3 data).

With the advent of the chip and pin cards in the USA, it seems logical that just about everyone upgraded to equipment that does support it; which might explain why you are only seeing this in the past year.

So, this seems a little opposite of what I meant. Naive me always assumed I pay with a card, the store gets my cc info to charge and we part ways. I'm getting in the mail ads from Meijer, for items I buy frequently. This tells me they were able to extract my home address and name from my credit card. Is that accurate?

I worked for the largest merchant acquirer ~11 years ago, and we were collecting SKU-level data for Wal-mart at that time.

Yes, these data are all available, if you are willing to pay to get those.

I noticed that now when my employees buy from staples.com, my AmEx statement will show everything they bought. From a manager's perspective, it's kind of awesome because you don't need to keep track of little receipts.