5+ books read. More tweets read than in the past two years (twitter is not for me but is where a lot of the Readathon action takes place).
Lots of reviews, reading progresses and posts to catch up on.
In terms of reading, went great. Posting and reading posts, way less than usual. Which I didn't expect because I tend to keep up with all the social activity, discussions and posts in solid hour-after-hour readathons while this one let me space out the 24 hours however I wanted in a 48-hour period. I think it's because this one seems to be mostly on individual blogs, Twitter and sites I don't use while the others I've done -- particulalry Deweys -- have been quite active on booklikes, Librarything and the mothership goodreads groups (my groups over there are basically all I do on goodreads).
Way, way, way less participation in whatever-hourly challenges. (Well, with mostly ebooks nowadays e spine one wasn't for me unless I started moving boxes of stored books around and ransacking physical bookshelves -- even then, I don't think most of my book titles would work well).
I'm not completley surprised at how few tagged-24in48 posts I did see during the Readathon (assuming others also did more reading than posting unless they forgot to tag their posts).