The other day, I went to buy dog food at my local pet shop. I bought a large bag of dog food and some treats for my dog that claimed to be able to make her breath smell better. Toothbrush-shaped treats. I paid with my Chase Visa card and walked out of the store. A few minutes later, I happened to check Twitter and saw an advertisement pop up — for toothbrush-shaped dog treats. I thought: this was not an online purchase. I used nothing but my credit card. How did this happen?
The advertising was too specific to have been pulled from the geolocation of my phone, even though my iPhone was in my pocket and certainly knew that I was more or less at the location of a pet food store. If that was the case, then I could have been offered an advertisement for cat food, or normal dog food, or bird food, or any of the other hundreds of items on sale. But it was the toothbrush-shaped dog treats.