From that same letter, the FAA seems to strongly imply it's ok to ask your friends if they want a ride on Facebook (say by posting in your own feed) but not ok

From that same letter, the FAA seems to strongly imply it's ok to ask your friends if they want a ride on Facebook (say by posting in your own feed) but not ok to ask the General Public by 'holding out' (by posting in a public group on Facebook). "Holding out is accomplished when one communicates to the public, or a segment to the public, that transportation services are indiscriminately available to any person with whom contact is made." Signing up for FlyteNow and playing around with the website makes it pretty clear there is 'holding out' going on here. Which is a shame because it's a rather nice idea and more akin to carpooling aggregators than Lyft or Uber. Being able to see if pilots have previous airline or military experience is a plus too.