[gumby]

I don't see it, since people could list themselves on competing listing sites just as the same drivers list themselves on both Uber and Lyft.

Then again you could say the same for eBay, yet Amazon couldn't get a competitor off the ground. One small moat (eBay has vs Airbnb model) is that you can automate the sale on eBay (so you'd have a hard time listing the same item on two sites -- you might sell it twice) while Airbnb still has manual intervention.