Yesterday David King proposed that the BIGWIG Social Software Showcase was the most attended program at ALA 2007, counting both the in person groups of 30 or so and the online audience. Cuz you didn't have to be physically there. As I'm not really doing anything but mapping directions to Target and IKEA in Chicago, I decided to add up all of the presentation page views from the wiki, plus the number of folks who watched the Twitter screencasts. I don't have the numbers for any of the other interactive content.
The unofficial audience for the showcase as of 12:30 EDT today is:
I haven't seen actual numbers of physical attendees for ALA, but let's assume that it is around 20,000. So that's about a THIRD of the people who came to DC. Of course people probably watched multiple presentations, but still. That's pretty awesome. And since the material is available online the number is only going to go up.