While not a record-breaking sale (last year's tickets sold out in under 30 minutes), the sale period again shows how hot the developer event is.
Regular attendees pay $900, while reduced $300 tickets apply for students and faculty staff. Of course, you have got to remember that all attendees get all sort of high-tech freebies, easily matching the ticket value.
Another important note is that Google I/O is not merely a developer's conference, it's also a venue for some pretty major product announcements and tech demos - getting everybody a first glimpse of Android's next release.