I agree, the main problem with the link going to the register page is that there's the possibility they may sell or redistribute your e-mail address to bulk e-mailers. So you may have to trade off the benefit of a free Poser item with an increase in spam in your mailbox. If people have reason to believe that the guy with the register page is selling or redistributing e-mail addresses, he's going to want to prove he isn't doing it. Maybe it would help to have a statement somewhere on the guy's web-page that he's not going to be selling or redistributing e-mail addresses. Then he would have to avoid breaking that pledge, whether by acts of ommission (allowing the server owners to harvest the e-mail data without his knowledge) or commission (periodically sending his e-mail database to bulk e-mailers).