Karl Brazier, Other options
What about "Did not attend in the past, but will attend rather than watch in the future"?
I probably would not buy videos when I can read the papers for free as a SIGKDD member...
Ralf Klinkenberg, Conferences = Presentations + Meeting People
Conferences are not only about attending and listening to presentations, but also about meeting people and about discussing and exchanging ideas. Both aspects are important. But the longer I am in the field and the more conferences I attend, the more I value the latter aspect. Hence, from my point of view, videos will not replace conferences, but they could be a valueable addition and added value, because it is impossible to attend all relevant conferences in the field as a single person and the videos would allow to take a look at the most important videos when you missed a conference.