From the interweb:
"Generally speaking, tax credits only offset tax balances due - meaning if you have low income and owe nothing in tax, you get no benefit from a credit. Whereas, tax rebates are paid to a taxpayer regardless whether a tax is payable. So, that's the difference between a credit and a rebate."
That is the way I had understood it. You pay taxes every year right? ....right? After you've hidden your money offshore or gotten deductions for owning a home excetra, do you owe any money? If you do, you get up to $7,500 of it back. So you do all your taxes and you're left owing a hundred bucks you get that hundred bucks.
Some seem to be saying you can double-dip. So you really owe 10 grand in taxes before you do all your shenanigans and owe nothing after but you then get to take another $7,500 because before all your deductions you owed that or more, even if you would not have had to pay it? Seems that would be barely any different than a rebate and help even more people that don't really need the help.