Thank you! The deals that I post and distribute are sourced from a variety of sources including manual searching with tools like Google Flights / QPX (like Scott's team), programmatic searching (expensive as others have mentioned in the comments here), forums or blogs, and of course Concorde's "Discover" tool. The Discover tool makes use of a cache of flight search data that is collected from Global Distribution Systems (GDS) such as Sabre and others. Further reading on GDS's: https://en.wikipedia.org/wiki/Global_distribution_system