They call themselves the “flight hackers”, who will compete to find you the lowest possible fare in return for a $29 finder’s fee, which is refundable if you’re not satisfied. The fee is entirely refundable if you don’t get the savings you want. Also, you can mention unusual requirements, such as your friend may be taking a different return flight or you may be carrying your dog along. It’s an alternative to using a travel agent, and the fee covers each person/ticket on the trip (rather than having to pay a fee per ticket).
The website lists an average savings of $373 on base flight prices, but if you browse past savings you’ll see that international and multi-city flights can get you some savings if you let someone else do the search for you rather than going the traditional Kayak or Expedia route: In a Canberra, Australia to San Francisco, CA contest, the price saved was $2,252 per person (24%), and a flight from Singapore to Hartford, CT $1,203 saved per person (54%).
Worth a consideration, at least, if you have a big flight coming up and don’t want to spend hours shopping for it.