There is if you get non-monetary benefits such as a 5 star review pushing you up in the rankings, thereby making it much easier to get future bookings at higher prices.

Edit: conceptually, it's nore like an unpaid internship. I know someone who got a highly paid job by first doing it for free for 3 months to prove his skills, as he was lacking formal certifications

Edit2: I honestly don't get why this is being downvoted. It's neither unfriendly nor offensive and it is relevant to the discussion, even if you might not like this aspect of reality.