I've seen on many sites the option "refer a friend". I want to use it on my sites also, but I'm concerned that can be transformed into spam. For instance, the owner of the site can pose as the friend that sends the eMail and send it to five unknown persons. What do you think about that?
referring a friend cannot be considered as spam. besides, a site owner will not pose as a friend and send it to unknown persons. its his site and he doesn;t wanna get caught spamming
Gmail uses an invite system and I've been invited several times by friends. I consider spam from friends spam... I wont use, or even condone the use of the "email a friend" pages anyway. Most seem a bit shady as if they are just collecting email addresses. For each person that refers the site gets to add two new addresses to their database. I have sent things to people I do not like though...but that's because I assume they think like me and will consider it spam. Of course I do not use my standard email for such things. Ultimately, if most people want to share your site with the people they know they will email the link themselves, or better yet blog about it.