At least it was last year. We get the check box as well. One time I took them up on the offer to get two $10 rebate checks (one per reservation). I applied for my rebate checks and then called & cancelled the Active.com membership a couple of days before the trial period ended. Got my $20 a few weeks later! The way I see it, I got my reservation fees back that year.
Also, in the past I have changed reservations (with the proper notice before checkin) without any fees. I don't mind RA, but be aware to look for the opt-out check box.