First, thanks for the well-researched post! It’s good to have clear numbers, and it’s certainly not great if a mailing list consists mostly of WeeklyOSM updates. Of course, that doesn’t mean that these lists would be more active if it wasn’t for those updates… but it’s hard to know whether or not that’s the case without running an experiment.
I can see a few problems with that solution:
- It cannot be a one-time action because people joining the community in the future should learn about WeeklyOSM as well.
- It requires either handing over the addresses of subscribers to WeeklyOSM (breach of privacy) or the WeeklyOSM newsletter being operated by the OSMF and WeeklyOSM losing some of its independence.
- There may be legal issues because subscribing people to a mailing list or newsletter is generally considered to require opt-in whereas sending email to a list they’re already subscribed carries no such expectations. Yes, even if the practical result is not that different.
I do agree that matrioska subscriptions, as you call them, aren’t ideal and I find them annoying on some (non-OSM) lists I’m subscribed to. But I can’t really see a pragmatic alternative. Some platforms, such as the Austrian forum, seem to have settled on posting WeeklyOSM updates as answers to an existing thread instead of opening a new thread each time, which I guess makes them a little easier to ignore if you don’t want them.