We’ve received the Nielsen fast-national ratings (not the actual national ratings) and have a sense of how last night’s Countdown with Keith Olbermann did in its premiere on NBC. The upshot: in total viewers it beat “Are You Smarter Than A 5th Grader?” on Fox. But finished behind “60 Minutes” and “America’s Funniest Videos.” 4,146,000 total viewers watched.

Countdown finished fourth in the 18-49 and 25-54 demos.

In a post last night , I asked how Olbermann’s NBC show played in the plains. Aaron Barnhart of that plain-worthy state, Missouri wrote about it in his blog TVBarn.com.

>More: An emailer writes, “4M viewers…is one hell of a sampling…I wouldn’t kiss that number off.” For context: Olbermann averaged 721,000 viewers each night in July. Almost 6 times as many watched last night.

> Update: The actual ratings for Countdown was 3,019,000 viewers.