What do youbmean by that? When I buy something at Target stores, they have absolutely no way to attribute whether I saw something on TV, a billboard, the aisle, their junk mail in my mailbox, or online.
I believe that Google can link in-store purchases to online ad exposure for most credit card users in the US. They've done this by doing a deal with MasterCard to integrate sales data cookie data. https://www.bloomberg.com/news/articles/2018-08-30/google-an...
Not where you specifically saw it, but in aggregate they can track things like purchase volume after a specific ad airs in a specific market or what was advertised in the circular, etc. They could vary things slightly by market as well to help pinpoint what's most impactful.
