HBO renews 'Boardwalk Empire,' ratings set record

HBO's critically acclaimed "Boardwalk Empire" delivered a big surprise in the ratings -- and the network quickly rewarded the drama with a second-season order.

The Sunday night premiere was the premium network's most-watched premiere of any program in six years (since "Deadwood" in 2004).

Adding two additional repeats, the "Boardwalk" number rose to a combined 7.1 million viewers. Despite glowing reviews, performance expectations have been modest for the Martin Scorsese-produced, Prohibition-era gangster drama. Some analysts expected the 1920s setting to turn off viewers and the show to draw a "Mad Men"-sized number.

Shortly after the ratings were revealed Tuesday morning, HBO announced a second-season pickup.

Renewing a show after one episode is rare, but not unheard of -- particularly among premium cable networks where ratings can (for awhile, at least) take a backseat to brand-building prestige. Earlier this summer, HBO announced a second season for its critically acclaimed "Treme" after its first episode. Later in the season, some questioned the wisdom of having such a quick trigger finger when critical reaction and ratings took a negative turn.

While I don't know that the drama will maintain its audience (one Live Feed commenter dubbed the show "Bored Walk"), I can tell you that critics will remain impressed. The show gets progressively stronger through its first six episodes.