AMC’s flagship drama Mad Men came back strong last night but might be plateauing in the ratings. Last night’s Season 4 premiere drew 2.9 million viewers. That was 5% higher from the 2.8 million who tuned in for the Season 3 debut last summer when the show’s audience grew 34% year-to-year. The 2.9 million mark marks a new series high for Mad Men and a new viewership record for an AMC original series.