Roger,
We do have a trial, but it is very hidden.
http://www.penthouse.com/free/join.html
I liked bradshaws post because it pointed out the imperfect math involved in computing retention rates, and i am a bit of a math nerd.
I know the retention rate, and mean subscription length computed in a number of different ways. I just mentioned i like looking at it as a percent rather than a length in time because declines are a not insignificant part of my cancelations.
I don't have a revshare or PPS now.