I went on Facebook yesterday and there was an ad from a retailer I used once ages ago that said, "We noticed you haven't shopped with us for a while, blah blah,

I went on Facebook yesterday and there was an ad from a retailer I used once ages ago that said, "We noticed you haven't shopped with us for a while, blah blah, here's a special offer". I use uBlock and have Pi-hole blocking stuff like this at the DNS level, so how have they been able to connect my accounts in such a way the retailer can target me? They even use different email addresses.