The additional advantage of this model is that Tesla, in turn, is able to collect data from the vehicles its built that use AutoPilot, and use that information to improve the system. Nonetheless, it's struggled to achieve the sort of autonomy it's been touting for years, and it still has to meet regulatory approval before any of us will be sleeping in our cars while they're in motion (though that hasn't stopped some Tesla users from trying already).
Eventually, Tesla believes it'll be possible for owners to have their cars serve as income-generating autonomous taxis when not in use, which could further reduce the cost of ownership while also helping the company realize some of its sustainability goals by reducing the number of cars needed on the road, and increasing the number that are emissions-free.