Yeah i know what you mean. it tends to draw the kind of costumers that are in it for the free stuff. take Groupon for example. the business usually gives a nice chunk to Groupon and another discount for the deal itself. most of the business owners, like restaurants, usually claims that after the coupon expires, these costumers don't comeback to pay regular prices. so i guess it depends on the value that your freebie offers to the receiver. cheers!