There is a Q&A with Jerry Seinfeld in WSJ today [sub. needed]. The questions were under the heading “Creativity”.

This is the best exchange:

WSJ: Most ad folks think the 30-second commercial is the optimal format. Your “Webisode” lasts for several minutes. Do consumers have that long an attention span?

Mr. Seinfeld: There is no such thing as an attention span. There is only the quality of what you are viewing. This whole idea of an attention span is, I think, a misnomer. People have infinite attention if you are entertaining them.