There's a good reason you aren't flipping away from ABC. And we're not just talking about Desperate Housewives or Lost. This season, ABC executives have changed the way they schedule commercials during their shows, using a little trick to keep you from changing the channel.
Typically, one-hour dramas start with a short scene, run the opening titles and then cut to a commercial. But now ABC's shows start with a complete "act" to get viewers fully hooked before they bring in the first ad. That's why the Alias season premiere ran a full 20 minutes before the credits rolled.
ABC's shows also have action after the last set of commercials, so there are no breaks between programs (when viewers reach for their remotes most). ABC executives who have looked at minute-by-minute Nielsen ratings say they've seen a "pretty dramatic" improvement. So expect NBC and CBS to follow suit.