Right, I know a guy at IBill who has his own paysites.
But is it ethical for the company to be competing with you? Not really, is it ethical for them to use the info you give them to build an email list? DEFINATELY NOT.
Unfortunately this is a new industry and a lot of those in it are new businessmen and therefore not good. We have to live with that fact.
I was considering using NetBilling for processing on my content stores, would I consider them for paysites? NO, because if this is their ethics who is to say what else they will do.
The other thing is the blatant way they sent the email, no attempt to hide the fact they have fingers in both pies.