Can you have the same refs sign up for all of your sites?

Hello,

I just have a quick question.... Can the same people that sign up for my ipodnano sign up for all of other freepay sites? My relatives are willing to do that for me for.......... a fee (ofcourse), but I'm not sure if this is o.k before I pay them. Thank you for reading.

ya it is as long as they only do each site once and they do different offers.