We've hosted both in Japan. It's a very different atmosphere, couchsurfers tend to be long time world traveling hippie types that are interesting to host just t

We've hosted both in Japan. It's a very different atmosphere, couchsurfers tend to be long time world traveling hippie types that are interesting to host just to hear their stories and help them out. They often arrive by hitch hiking and we've even had some who are walking hundreds of km across Japan. Surfers have low expectations for accommodation and usually the day is spent chatting and going to places together. AirBnB is for example couples and people who expect something closer to a hotel and more privacy, they may be busier and prefer to pay for convenience. Say career people who only have a week or two to spend in Japan, so they pay to make things go as smoothly as possible.