No, it is not legit IMO.

In order to share expenses, all occupants must have a common purpose for the flight (ex $100 hamburger or weekend getaway).

If the pax want to go somewhere, but the pilot does not really want to go there and is just along to fly the airplane that would count as an illegal charter business.

And the FAA would consider the pilot to NOT be paying his fair share...he is obviously building flight time, which will be considered a form of compensation.

This WOULD actually be legal if he took only pilots, who also needed to build time. In that case all pax have a common purpose, and are paying the same share and getting the same benefit out of the flight (assuming everyone takes equal turns at the controls).

But non-pilots who just want to get from Point A to Point B? No way...

If you can, get hold of this guy and clue him in before somebody refers the FAA to his ad.