I get Orbitz and the others being unhappy about this site, but I don't think i've ever heard the term "unfair competition" before. Isn't that just capitalism? For those that don't know, Skiplagged figures out "hidden city" airfares. From the story: http://www.cbsnews.com/news/finding-cheap-airfare-made-easier-with-skiplagged-startup/ http://boingboing.net/2014/12/30/united-and-orbitz-sue-skiplagg.html
Kind of cool that someone created an algorithm to look for these. I've actually been doing it for years, albeit manually. Denver to Phoenix = $300 on average. Denver to San Jose through Phoenix = $260. I just buy the San Jose trip and hop off in Phoenix. Typically only works in one direction. If you find a round trip that connects using the exact same route, you can print off your connecting flight only and you are on your way.