The poster above is correct. The commission can be used toward closing costs, or even buying the price down of the home (usually the lender will dictate how it to be used).

One thing to consider is that the Realtor pays taxes on the full commission amount even if he contributes some of the money. The only way around that is to have the client claim the money as income and the Realtor to deduct it from his at year end.

It is illegal to give cash back at closing, since it wasn't disclosed in the closing statements. The lenders consider that fraud.