I worked the program like crazy and learned a lot about carpet retailers. They didn't like the program and didn't want to give their database to some guy in Chicago. Many just wanted a kickback for referrals, and if someone walked in tomorrow and would give them 1% more they'd see if you'd give them 2% more or they'd switch.
One said, "It's a different world today, and we're not making enough money to be good guys." Another said, "Cut the crap and just pay our salespeople a commission to sell carpet cleaning." The most common comment though, was that they needed to sell color and warm fuzzy, the last thing they wanted to talk to customers about was the negative of handling spots and dirt, so the warranty program was actually a sale killer for them.
I can see it working for certain cleaners and certain retailers though, so if you're thinking about the program you might try talking to some local retailers before you jump in.