i noticed only 26 players online, which is the lowest i have seen, with 90+ being the most i have seen, considering i am new i have not seen what the population used to be, but have noticed in older shots some shots getting 1400+ solvers on a single pic... I will be trying to recruit people to this site on imdb, without making my self look like a spammer, i.e. i will be holding snapshot quizzes on imdb forums with the url to this site on the post to try to attract players.. I noticed this site is 5 yrs old, but perhaps most of the players are old players back from when the site attracted alot of players...
I think you have to take into account that it is holiday season. I guess a lot of people who now are away will return in the new year.
Also I'm not quite sure if you can compare the number of solutions on old shots to new ones. I think there was a time, when archive solves still increased the counter, but I'm not sure. However, one of my easy shots I posted last month still got over 1'000 solves ( http://whatthemovie.com/shot/293846 ). So I don't think there is a big fall in population. Still, a mod might give you a more precise answer.
Furthermore, there is a substantial group of loyal people who is active for several years now. In my case it is more than five years. I posted my first shot on September 29, 2008 ( http://whatthemovie.com/shot/3209 ). And I started solving a few weeks earlier.
that ss is an easy one though, I notice on old pics for a ss 4-5 yrs ago that'd reach about 1400-1500, I feel there is a good amount of people, I am new and want to stick around for a long time because this site is just what I have been looking for!