I get my mails a bit arbitrarily, as I'm changing computers and reconfiguring mailboxes to separate business from private. Sorry to those that addressed me, if I did not answer in a reasonable time.
I just want to answer to the argument, that airbnb should limit itself to be a booking service. We started renting 2003 and there were already online booking services, mostly advertising services for short term rentals. They got a bit more sophisticated over time and merged into a few big ones, losing efficiency for the advertisers on the way, taking years to make small changes, which half the time did not improve the service.
Then came airbnb with a very different concept. A booking service. Handling payments. Technologically as advanced as can be. Creating websites and applications that are addictive and fun to use - who of you never travelled around the world on the website or app, just for fun? Doing a bit of "vetting" by creating user profiles that get reviews.
All of that is a good business offer and much better than everything that existed before or was copied in the first years (I did not check recently). But that alone would still not explain the success.
The success comes from the brand image airbnb could create. The lifestyle they represent: young, cool, easy, fast, professional, succesful, free (liberty), sharing, connecting the whole world, making everyone belong everywhere. Etc - you get the updates from Open to Open. And it's even called an Open 😉
That image is a political statement and it's one that allows to make huge amounts of money - to the company and also to us. (Not on the same scale, but still, I'm satisfied with my share).
If airbnb reduced itself to be only a booking service, it would be gone within a few years. 20 % or less of hosts would be back to look for new booking websites every 2 years and the rest would be out of business, as there is a lot of knowledge involved, which airbnb newbies get served in an easy to handle app on their smartphone.
About 100 high tech companies made the same decision, to make a public statement, and I'm pretty sure their CEOs thought about it very carefully and decided that it would be useful or even necessary for their brand image and further business success.