[minthd]

Sure there are risks. But assuming that lyft-line or uber-pool succeed in filing rides with few people in return for lower costs they will have an advantage, because average occupancy and a reasonable ride length is highly dependent on amount/density of users.

And BTW, according to some uncofirmed twit[1], more than 50% of lyft rides in sf are done through lyft-line, which is a pretty new service.

To a lesser extent, user density is also related(in theory) to driver ride time, both in reducing wait time, and reducing time from call to passenger.

Also there might be a possibility they can subtly incentivize drivers to only drive for them by giving complying drivers a bit more work, or better work.

And as for your risks lists,you can paraphrase it as: the hand of god(government), a darpa scale technology(self driving cars), very well resourced competitor.

But every company is under risk from the first 2, even for businesses with a strong competitive advantage.

[1]https://twitter.com/DavidELPC/status/593832295968059392