[Baeocystin]

Posting to confirm, having seen back-end sales numbers from (admittedly much smaller) vendors, the correlation between $just_bought_thing and $will_buy_another is very, very high, across pretty much every category I cared to look at.

[jodrellblank]

But surely if you just bought a <Roomba> and like it and intend to buy it again as a gift then you don’t need an advert for Roombas - (and showing you such an advert followed by you buying another Roomba is making the advert look more effective than it was) - and you definitely don’t need an advert for Bissel or Dyson, and you definitely don’t need a dozen adverts for Amazon PLINGBA BEST VACUUM, TYBCHO VACUUM EXPERT, DAOLPTRY VACUUM CLANER etc etc?

[Baeocystin]

Showing someone ads for products in a category they recently purchased from is one of the most effective things a store can do, in terms of focused advertising driving sales. We can wonder why, but the data is exceedingly clear.