As of this posting: Adventure - 454 Chicklit - 255 Erotic Fiction - 113 Fantasy - 3191 Historical Fiction - 394 Horror & Thriller - 515 Literary Fiction - 797 Mainstream Fiction - 678 Mystery & Suspense - 574 Religious, Spiritual & New Age - 110 Romance - 618 Satire, Humor & Parody - 382 Science Fiction - 1209 Young Adult & Youth - 1052 Other Genres - 969 Unreported - 38982
It's interesting to compare these numbers with, say, the numbers from 2005 and 2006 at about the same time. The genres with the least number of participants is, as always, erotic fiction and religious fiction. (What is it about the sacred and profane that have everyone shying away?) Also, back in 2005, almost twice as many people were doing literary fiction as compared to science fiction. Whereas this year, it's the reverse. Fantasy again tops the board, although there aren't as many people in Other Genres (but this may be attributed to the addition of Adventure and Mainstream).
I also have this theory that participants get thinned out by half every year (see stats from 2006). If we go by "sign-up date" with the caveats that anyone who signed up during 2002 includes 2002, 2001, 2000, and 1999, and that sign-ups continued after November 30 in 2007, so only people who signed up before December 1, 2007 counted as having participated in 2007, we have:
There's certainly a decrease (example: this year's "2002 participants" number 630 while two years ago it was 1084), but it wasn't that drastic. But whatever is happening, I'm sure that there's probably only a relatively small core who will return every year.