forget all the shit of cam scripts who you can buy.... they all sell software that's 5 year behind.... one has some crappy java server another one provide only hosted solutions and and and... they have all together that you never will make serious money with them :-)
Some functionality that is needed that you can make money today apart marketing:
free preview / free cams is a nice way to bind users, the bad is the need bandwidth cost and this because they don't use RTMFP over FMES or Adobe Services which would reduce them by 80%.... and you can stream HD for free too
they use standalone encoders for H.264 means the broadcaster must install some software that mostly connect to a local installed Adobe Media Encoder.... since Flash 11 this is not anymore needed, it has a builtin H.264 encoder....
and now the most important: why no one integrate various micropayment solutions that would allow that the user in a easy way (and most important: mostly anonymous) use the service, spend tips, send gifts or whatever....
there exist many more points, fact is: if you want earn serious money develop a custom solution that really works.... if you don't have the money for it be a affiliate.