TechCrunch reports that, per an FAA ruling released today, the new rules prohibit pilots "from publicly offering seats on their planes in exchange for gas money." This will affect startups like Flytenow (which matches people who want to fly small with pilots) and Airpooler (a company that describes itself as the Lyft of private planes).
The FAA addressed its statement to Airpooler, which requested legal clarification from the agency last month on whether it is running a legitimate business.
Why draw the line at private planes? The FAA says transporting passengers in exchange for fuel qualifies as being compensated for airfare, even if the pilot chooses the destination she wants to fly to. The language seems to suggest that because Airpooler pilots can list flights on the company's website (and wait until there is a demand), it's akin to allowing customers to buy their flight the old fashioned way—commercially.
Read the rest of the FAA's decision at TechCrunch.