Last night’s debut of MSNBC’s “Rachel Maddow Show” was a rousing success in terms of the strategic goals the network set for the program. The premiere broadcast drew 483,000 viewers in the advertiser-friendly 25-54 demographic. That was good enough for a second place finish versus the competition, beating the veteran Larry King. She also was the second highest rated program on the MSNBC prime time lineup, following Keith Olbermann’s Countdown.

Most importantly, however, was the impact Maddow had on the schedule. One of MSNBC’s weak points is that their programs provide little encouragement to viewers to stay tuned for very long. The mix of content offered by Olbermann, Chris Matthews, David Gregory, and the now canceled Dan Abrams and Tucker Carlson, was disjointed and incongruous.

Abrams’ Verdict, which Maddow replaced, failed to retain even 50% of Olbermann’s lead-in (averaged for July 2008). Maddow, on the other hand, managed to hold 80% of Countdown’s audience. That sort of retention can go a long way toward building a programming block that competitors will find challenging to confront.

This is, of course, the results of just one day. Time will tell if the strategy works over the long run. But it is a promising debut and a foundation on which to build. Plus, just having Maddow’s sharp insight and reasoned analysis injected into the whirlwind of cable talkathons for the next few weeks leading up to the presidential election in November, is a positive development for those interested in an engaged and informed electorate.