Now why doesn't that sound like a good idea? It is however a good way to increase sales, according to a Missouri car dealer. He ran a week long promotion where he gave away either a $250 gas card or $250 credit for a gun shop. As a result his sales soared and he managed to sell 30 trucks in just three days, much more than the usual volume. All the buyers except one elected to take advantage of the gun credit rather than the gas.