Their frequent flyer program is basically subpar (and was only added relatively recently), which kept business travelers off. (I like the Virgin America product, but if I can fly United and get upgraded to First, lounges, etc. and earn miles toward flying in International Business or First to Asia for fun, I'll probably suffer through a United transcontinental over a Virgin America flight...)

They won the leisure market to/from SFO, but that's not a big enough market to be a successful airline.