I have a question about pay per signups (PPS) that never really occured to me until now.

Let's say a surfer clicks on the PPS link in your blog and ends up joining the site, then you get the $30, $35 or whatever PPS commission. The surfer cancels their membership after a month or two... but then, let's say six months later the same surfer visits your blog and ends up joining the same site again after clicking on your PPS link.

So what I'm basically asking is: do you keep getting PPS credits from the same customer if they join and rejoin, or are PPS sales a one-time per customer thing? And how much time (if any) must elapse between the same customer getting you a PPS sale?

I suppose it may be hard to answer this because each sponsor may have different policies, but generally speaking, what do you think the norm is in this matter? I would assume most sponsors might put a restriction on PPS sales because I think its normal for some people to only join a site for a month or two once or twice a year. A sponsor would probably lose money on PPS sales from these people.