I’ve updated the statistics that I regularly produce from our changeset dump, see stats page on wiki.openstreetmap.org, to the end of 2014 numbers.
The well known trends continue with growth in every category with a total of 472’925 contributors since 2005.
Looking back on the 10th anniversary celebrations in 2014 it is important to note that was celebrating the birth of the idea, not the start of success.
Success slowly started in 2007 with the project taking off in 2008, for a Web 2.0 undertaking prior to that it was a flop. Perhaps even better than a graph Martijn van Exel’s “then and now” map comparision with 2007 illustrated just how much of nothing OSM was back then (unluckily the comparision is no longer available).
It is diffcult to nail down why the sudden change in course happened, likely it was more the pieces of a puzzle falling in place than just one cause. However if asked to point to a single person and event, I would clearly point to Richard Fairhurst and the Potlatch editor being the pivotal person and thing that changed the course of history for OSM.