Personally I don't have any experience in selling that stuff but here in europe it must sell like crazy - german MTV and another german music channel VIVA got nothing but ringtones (and other stuff for cellphones) commercials - it's fucking crazy but it's really hard to watch other commercial on those channels - I think there are two major companies involved in his biz and they buy whole, and I really mean it, commercials time
I know there are some kinds of abos so it's like reccuring in some meaning but don't really know details as I've never bought or sold any ringtone
All I know it must be next, after porn, money maker these days (at least in europe)
these are the websites of those companies if it helps anyone
http://jamba.de (as I see it's
http://www.jamster.com in US) and
http://zed.de/