I've read that these ads target you because by buying a dish washer your category went from "no idea" to "people who buy dish washers online". So while your cha

I've read that these ads target you because by buying a dish washer your category went from "no idea" to "people who buy dish washers online". So while your chance of purchasing a dish washer right now might be low, as you just bought one, the calculated probability of you buying one has actually gone up. Additionally, it alleviates the creepiness factor a bit ("they're so bad at tracking, they don't even realize I just bought one!", so you don't think about the perfect match with headphones you were just offered) and they might simply have missed the purchase.