[ramit]

Great question.

No, we haven't split-tested the addition of Paypal. We're constantly running tests, but this is a low-priority one for us based on extensive customer research.

Since we can't test it all, we pick the biggest potential wins (e.g., headlines and offers) and run them as rigorously as possible.

I do know that IMVU offers an insane number of payment options, but I think this may have more to do with their particular userbase.