With the decline in prices, and scarcity of buyers, it may be tempting for a seller to fall for this scheme, but be careful, it could be one of the mortgage fraud schemes that are going around! 

The basic idea is that after a property has failed to sell, a buyer comes in and offers to pay above asking price, and the seller will rebate the difference back to the buyer.  Read the details of how this works, and be careful that you don't fall for it!