saturation

I've been looking at the site records and new gallery creation seems to be slowing down.

One possible explanation I came up with was, "Everyone who knows about this site and wants a cel gallery already has one." Cel collectors aren't the largest demographic in the universe. Six hundred or so collectors is probably the most you would ever find at even the largest of conventions (of the US ones, at least).

Could it be something else? Are there fewer collectors than there were three years ago? Is the language barrier a problem? Who else do you think should we tell about this site?

I think it has more to do with the fact that most collectors signed themselves up with Rubberslug when it first opened. Now that they're all here, only stragglers like me are signing up (and I'm sure we're few in numbers).
I really don't think it has much to do with the collecting community diminishing, but rather that when this site first opened there was a huge rush, and now the site is experiencing the normal flow of new collectors.