On Monday, we enabled an ad space on documentation pages hosted on readthedocs.org. We have tested the ad space in the past, and had followed up with a discussion of the implications of advertising. The space was meant to be totally unobtrusive to the browsing and usage of documentation pages, and doesn’t enable third-party tracking of users in any way. This is all in an effort to help raise funds to support continued support and maintenance on the project, and ensure free and open documentation stays available.
Read the Docs is a massive project, and requires a large amount of work to keep running and support. We receive support requests and must tend to the operations of the servers on a daily basis. Neither of these tasks lend to volunteer contributions, they both require dedicated support roles for such a large site. I’ve personally been wearing a pager in support of the project for over 4 years, all on a volunteer basis.