OK, thanks Tilman and Jon. I look forward to seeing the mobile web retention info.
Encouraging mobile users to contribute to Wikidata makes sense.
I think there could be gamified ways of encouraging contribution to Wikidata in particular, but perhaps also to infoboxes, maps, and Commons. However, getting quality contributions instead of spam, vandalism, nonsense, or low-quality contributions might be a challenge.
Editing full text Wikipedia articles by phone was painful when I last tried it on mobile web. I'm hoping that there have been improvements since that time, and that there will be such big improvements during the next FY that people will find editing full text articles only modestly more difficult on mobile than it is on desktop. That's ambitious, but given the trends toward mobile devices globally and that many people in less developed parts of the world may have access to Wikipedia Zero on their phones but no desktop access, I think that this direction is worth at least exploratory effort.