An article in The article in McKinsey quarterly (free subscription required, well worth the trouble for the interesting charts, statistics and analysis) attempts to cast some light on what is happening in the low-fare airlines business, and provides some good coverage on Ryanair.
However, I think the article misses out on the essential point: air transport is being turned into a business driven by scale and cost management.
Although old-style airlines can make more revenue-per-seat in the good times through having a premium offering, they aren’t making big enough margins to be able to weather bad times in the future. The only thing that is saving them from fire and brimstone at the moment is that they are able to hold on to slots and gates at all the convenient city airports.