Why is the percentage less for rebills? That would stop me right there....
But to give you an idea ...on all my single model sites I do no less than 50% on signups and rebills (my site is 60% + bonus program up to 70% with 10% WM Referrals)
and a minimum of 10 hosted galleries and lots of zipped content as well .
None of that is worth 1 cent however without a really hot converting tour and site design, IMO ....
Ivy