How do they enforce the "Limit 1 per household rule"?

Question

There's this laptop at BestBuy that is limited only 1 per household. I'm just wondering how would they know if two people are from the same household and if they're buying with cash ( not credit card).

Or for example, those Thanksgiving shopping bargains. How would people know if people are from the same household?

Do they judge by appearance such as race, age, likeness?

Answer 1

I don't think they really mean that two people in the same house can not buy the item, it just means you can't buy more than one at a time.   Usually items that are limited to 1 per household are only in  stock in very limited availability, and they don't want 1 person going in and buying all the available items at one time.