American Airlines today announced they will be overhauling their entire mainline fleet to include extra legroom seating in economy, effectively matching United’s Economy Plus and Delta’s Economy Comfort offering. The new ‘Main Cabin Extra’ seats will feature four to six inches of additional legroom and include early boarding privileges.

AAdvantage Executive Platinum, Platinum and full-fare (Y) customers will have free access to these seats at the time of booking, and as a promotional offering, American will allow Gold members complimentary access to Main Cabin Extra seats through December 31, 2013. Non-elites will have the option to purchase access for $8 to $108 per segment, depending on flight duration.

Beginning next week, United’s Premier customers will no longer be able to book Economy Plus seats at the time of booking, rather having to wait until check-in for complimentary access. American’s current FAQs do not mention if Gold elites will have similar access to Main Cabin Extra beyond December 31, 2013.

The carrier’s existing Preferred Seats program – typically all aisles and windows in the first half or so of the cabin – will remain in place, so the addition of Main Cabin Extra might make it incredibly difficult for a non-elite who isn’t interested in purchasing extra legroom or preferred seating from sitting anywhere other than near the lavatories in the rear. It remains to be seen if American will adjust the percentage of seats in this category due to the rollout of Main Cabin Extra.

This is a move in the right direction for American in terms of both enhancing loyalty and the all but certain boost in ancillary revenue so desperately needed. After I cross the million-miler mark with United, I just might return to flying American as I had fantastic experiences with them last year.