Federal Computer week has an interview with one of the operators of the White House web site. Here's an excerpt:
We
are moving toward a society that doesn't rely on the clock as much. If
you miss a TV program, you can record it, for example. [A] successful
Web site will offer all of [its] programming at any time of day. I
don't understand why networks aren't offering that now, really. If you
miss a TV program, you really should be able to go to their site and
watch it online at any time of day. Same goes for popular news
programs. You want to increase viewership and name recognition — put
the program on the site.