The outage that the real estate photographer directory had last week (the page wasn't down, I just couldn't add entries for a few days) confirmed my fears that the size of this kind of static directory page is limited. The size is limited by the maximum available memory on the PFRE blog's WordPress server. I increased the size of the memory available to WordPress the server but as the directory grows I'll run into this problem again.
I could get around this problem by converting to a database and having the directory page created each time the page is displayed. This is the way many directories like this are done. However, this solution would eliminate the positive "Google effect" that those in the directory get by having the top ranking site for real estate photography pointing to their site. So, rather than hiding the directory from Google spiders, I've decided to keep the directory page the way it is and eventually limit it's size. I won't know where the maximum size will be until I run out of server memory again. When that happens, I'll only accept as many directory registrations as there are people that don't renew each month and depending on the demand there may be an increase in the price of directory registration at some time in the future.
In the mean time, I'm going to manage the directory more closely than I have to date. This means I'm not going to allow directory entries for either parked domains or sites that are not clearly real estate photography related. I'm going through the directory now and removing all the old directory entries (the ones before 6/15/2008) that are parked (have no website ) and the ones that don't have anything to do with real estate photography. I'm also sending one renewal notice to the e-mail you used to register your directory entry with. So be sure you have control of your SPAM filter. If you don't renew, I'll immediately be deleting your directory entry so it can be used by someone else. I think this approach will best pass on the benefits that the PFRE blog has of having top Google authority for the search terms "real estate photographer" and "real estate photography".