It is not a gimmick - I've pulled down over $2,000 a year for the last two years. Some of the travel warriors at my company get $500-600 a month.
My guess is that within a few months the beatings that travel agents have received at the hands of the airlines will spread to this program and the % will be cut. I just received a $150 rebate on a flight that the agent got a $50 commission on.