This is an essay. It expresses the opinions and ideas of some mediawiki.org users, but may not have wide support. Feel free to update this page as needed, or use the discussion page to propose major changes.
"topics about the global south are not as strong in English Wikipedia… [Getting more content in these gaps…] that has an important effect for us as a movement, broadly. the more content there is in Wikipedia that is relevant to people in a certain part of the world, the more likely they are to use it and engage with it. It's sort of a self feeding cycle." 
Wikimedia is many things: a software platform, a global movement, a collaborative community. But for the vast majority of our daily users Wikimedia means one thing: informational content. Readers come to Wikimedia (and largely Wikipedia) for many reasons, primarily to satisfy an intrinsic curiosity, or to become more informed about something they see in other media. But no matter the motivation their satisfaction rests, finally, on one thing: relevant content. Satisfying this need for new users in new markets will be the key to encouraging growth in readership, just as it did in the early growth phase of Wikipedia.
This core user need also aligns with our strategic direction. That is, locally relevant content is not only a potential engine of growth in new markets, but filling these gaps in the content is core to combating the larger inequities in the knowledge that historically has been stored and shared on Wikimedia. By encouraging and enabling new content and topic growth in previously excluded areas, Wikimedia can drive not just growth for its own sake but equitable growth: growing specific audiences and content which have previously not been able or allowed to participate in global knowledge production and distribution.
C. McMahon, I. Johnson, and B. Hecht, 2017 The Substantial Interdependence of Wikipedia and Google: A Case Study on the Relationship Between Peer Production Communities and Information Technologies https://aaai.org/ocs/index.php/ICWSM/ICWSM17/paper/view/15623
- D.Scott, Lead Organizer of Wikimania 2018 https://www.youtube.com/watch?v=TTtb4dEypQk at roughly 22 minutes in
- We count approx 200,000 contibutors a month, and roughly 1B devices. The means 99.98% of use is non-contributory consumption. This undercounts as it doesn’t account for the readers reached through massive re-publication channels, such as the Knowledge Panel.
- “Interestingly, one of the barriers to adoption that this report cites is a lack of local content. “In trying to connect the unconnected to the internet, content has for many years been the forgotten ingredient, with efforts prioritised in expanding coverage and lowering the cost of ownership. These are, of course, fundamental, but so too is the question: is the internet relevant for me?” https://meta.wikimedia.org/wiki/Strategy/Wikimedia_movement/2017/Sources/Considering_2030:_Future_technology_trends_that_will_impact_the_Wikimedia_movement#cite_note-8 pointng to https://www.gsmaintelligence.com/research/?file=357f1541c77358e61787fac35259dc92& download slide
- There are a number of papers and books which examine the network effect and symbiotic growth between Google and English Wikipedia in the early years of the project. Anrew Lih’s is prbably the most narrative. Academic version: The Substantial Interdependence of Wikipedia and Google: A Case Study on the Relationship Between Peer Production Communities and Information Technologies