This question really belongs in meta.tex.stackexchange, but I just created an account and don't have enough rep to post there.
I used the June 2013 Stack Exchange data dump to look at the time series (by month) of the 5 most popular tags on tex.stackexchange. Here's a plot:
Interpretation is left to the reader.
This is more of a fun fact than a question (sorry about that), although I'd certainly like to hear any thoughts on other fun facts that could be had from this data.