Well my girlfriend just bought a laptop, it was broken, she returned it, she bought a different laptop, again broken, and now bought a third one. Looking at how many products are DOA nowadays, it might be that a person that just bought something is more likely to buy it again than the average person.

Also in general I've noticed there are a lot of people that return online purchases a lot, even the non broken ones, since you can't determine if the clothing fits, if the colors really look good, if it has a good texture, from pictures and descriptions online.

They may not be good customers, but Google probably gets money per purchase, not for customer quality.