Dane put is pretty well... because I get asked all the time, "what does your sites convert at" which really isn't a very simple question to answer, because traffic is different for different sites/people...
We have some guys that for every 50 or so hits they send us they get a join, others send thousands for each join... both are happy based on their traffic.
We always think the best thing for people to do, is compare "apples to apples" send us 10,000 hits and then send 10,000 from the same links, galleries, etc to someone else, based on your count of course, and then look at which made you more money...
