Last night the final season of Lost began with a double episode premiere, garnering an average of 12.1 million viewers. The good news is that this is about 6% more than last season’s premiere, and it’s also the first time since Season 2 that a premiere has a larger audience than its precursor. The better news is that the audience growth over-indexed in the 18-49 demographic, attracting more than 10% than last season.

The problem is that comparing yesterday’s performance with last season is somewhat lax since new audience lows were marked for both the premiere and finale last year. The 11th episode of last season also garnered the smallest audience of any first-run Lost episode to date: 10.8 million during the 11th episode. This was a far cry from the performance of first half of Season 2 when Lost was attracting over 20 million viewers.

As I mentioned in a posting back in March 2009, Lost has “lost” its audience due to its complicated serialized plotline, a weakness which was exacerbated by a long hiatus in the middle of Season 3 as well the 2007 writer’s strike which delayed and shortened Season 4. Luckily this season seems to be free from any similar debilitations so the series might end up growing its audience over the course of its last season, which if it were to happen might yield a rumored Lost spin-0ff.