We recently started to branch in this direction as well, however, it was rather inadvertent. A much larger website was interested in having our planning features from http://ridewithgps.com on their site, but didn't want to budget their own coders to implement it. We are in the process of negotiating a contract, which is turning out to be fairly lucrative for our small startup.

So, this works both large and small; just like Google Maps, you can give away some bits for free but if anyone wants to use your product in a way that will financially benefit them, they kick you a license fee.