Just in case you guys don't know this, since I don't see it mentioned anywhere, Dave is also the co-founder of ITA software which is basically the engine holdin

Just in case you guys don't know this, since I don't see it mentioned anywhere, Dave is also the co-founder of ITA software which is basically the engine holding up modern transportation. It powers almost all of the websites that deal in transportation (hipmunk, kayak, etc.), and this is, and I believe this is Dave's term, a fractal problem. Fractal problems are those that look really simple from 100,000 feet up (like a dot) and reach unimaginable complexity as you get closer (like a fractal). There are a lot of problems of this nature (like email, transportation, ecommerce, taxation, etc.) and solving them is worth a lot of money but requires a LOT of work.