There is no question in my mind about the immense benefit of hosting the videos and the PDFs/ODFs. I think if (1) the content was only made available 30 days after the conference, then registrations would not be affected and (2) 30 days, post-conference, it would kick the buzz back up.
Maybe, the highest rated events would be hosted so that (1) only the best would be seen and (2) it would encourage TED quality of presentations.
Maybe, the highest rated events would be hosted so that (1) only the best would be seen and (2) it would encourage TED quality of presentations.