I am working on putting together the beta for http://TripFate.com and thought it might be a good idea to share the story and motivation behind it.
I met my wife exactly 4 years ago - all thanks to being on the right flight at the right time. Funny thing is, I wasn't really supposed to be on that flight to Rome. As much as I loved traveling, I was a poor college student and I couldn't really afford the expensive flights.
And then it happened. I was looking for flights to random destinations after wrapping up my project report at 4 AM, and I found a round-trip ticket to Rome (from NYC) for ~$110! It was crazy because the usual prices are at least in the $350-400 range.
I got super hooked! After I returned from my trip, I registered on a bunch of websites to get alerts if there was a price drop. I did get some good deals, but nothing was as crazy cheap as the one I had found for my trip to Rome.
Long story short, I created a service for myself over the years that'd look for flights from across the internet that really were 'great' for their price. In the beginning, it simply sent API requests and had a bunch of if-else statements. However, over the years, I've added a bunch of Machine Learning and Deep Learning tricks to the algorithm.
Moreover, I have instances of my 'smart travel finder' running on around 14 different servers around the world (who knew looking for a flight from India is cheaper sometimes!).
I started getting lots of really interesting flights: ~$170 round-trip to Cancun, ~$230 to Paris, ~$340 to India... and so I decided to share it with family and friends and friends of friends. Once the list grew to over 200, I thought maybe people would be interested in paying for the service, and that's how http://TripFate.com was born.