From the Co-Exist article:

Imagine you’re moving apartments and shopping for new furniture at a couple of stores. You see a couch you like, but you’re not sure, so you leave thinking maybe you’ll return another day. But that couch doesn’t take well to rejection. It gets up, leaves the store, and starts following you around as you shop elsewhere and even after you go home having purchased a different couch. Then you start getting offers in the mail for new mattresses.