I've noticed that some of the "low cost carriers" (e.g. Southwest, Jet Blue) and some of the regional carriers (e.g. Atlantic Southeast Airlines) have all-leather seats, but some of the legacy carriers have cloth seats in economy class.

From what I've read, the all-leather seats are often chosen for ease of cleaning, but the side benefit is a marketing advantage, since leather is generally perceived as "more luxurious" by most people (personally, I am indifferent to cloth versus leather in airplanes, but I am probably in the minority with respect to how I view cloth and leather).

What would be the reason for using cloth seats in economy class? Presumably, it costs less, but it would seem to be a marketing disadvantage for the legacy carriers relative to the "low cost carriers" and even their own regional affiliates, and the ease of cleaning the leather seats may counteract some of the cost of installing leather seats.