I think they somewhat count on a lot of people getting to the point the monthly fee kicks in. 

I tend to spend the entire thing right away, whatever the amount is that goes over what's on the card I just pay. 

I've had rebate debit cards from 10 to 200 dollars and have always read all the paperwork.  Then I use them within a week of activation. Nothing I hate more than getting cheated on rebates!

Ok, there are a lot of things I hate more, but as far as rebates go, I hate to get cheated out of a single dime on them

There are a lot of other things you can pay with them,  insurance, phone bill, gas purchase, groceries etc.