How Do Convince Guests to Become Members?

My forum does not allow guests as many privledges as members because I want commitment. Joining my forum is completely free with no strings attached, so why have I seen so many guests visit my site, look around, and then leave without joining? Is it just a matter of time or am I doing something wrong?

That will always happen. I allow guests to view the areas that members can view, I allow them to post aswell but the posts have to be verified by an admin.

I also allow guests to vote in our battle of the bands poll. To me guests are very important if you are going to restrict permissions then they are more likely to find another forum.

I also think that guests want to see content. If I see a forum but I can't view the sections or posts then I won't join.

Theres offers I put up, and also I dont give out to much of the forum.

I allow Guests to read everything except the Announcements section and the Staff Only section. I only allow them to post in the Support, Games, and Prayer Requests sections.