I agree with Steve that it is a moot point now but I remember several years ago there was a period of time where only new members could see photos. Wearing my Moderator hat, I concluded at the time that maybe some people were joining the forum just to have access to the photos and without any intention of playing a more active role on the forum, which I thought was better for the forum. I therefore concluded that maybe it was better to just let guests see the photos again so that they wouldn't join just for that purpose and clog up the membership rolls. So, Steve changed things to let guests see photos again.
After watching the parade as a Moderator over a period of eight plus years, I now believe that most people join the forum mainly to find recipes, especially clone recipes of their favorite pizzas, to ask for help, to make a comment or observation on a pizza matter, to use the search engines (which they can only do it they are members), or because they are simply intrigued by what they see as guests and decide to join to explore the forum further. In that vein, we have also seen a dramatic increase in interest in Neapolitan style pizza and ovens and related mobile applications. However, the reality is that, no matter what the "system" is, people continue to join even though only a few percent of them make it out of the introductory stage and become active on the forum, even when they profess their undying love for pizza and say that they plan to become active participants. We are lucky to get two or three percent of the new members to play an active role.