Giving What We Can recently celebrated its 5th birthday. It's not much of a party if no-one external congratulates you, so here we go: Happy Birthday, GWWC!
It's pretty impressive how much GWWC has grown since those early days. Here's a chart of total membership, which I've put together from GWWC emails and liberal use of the internet archive. I'm sure they have better data (without gaps!) internally, but I've never seen this chart before. Notably, growth seems to have picked up since the fall of 2013. Did GWWC change their strategy at that point? (or their membership-counting-methodology?)
Putting the same chart on a log scale, we can see that GWWC have actually done a reasonably good job of sustaining exponential growth.
Fitting a line of best fit to the chart, I estimate GWWC's membership is growing 73.1% a year. Assuming 2% population growth, it will take just 30.25 years before all the world's population are GWWC members. Taking over the world by the time I'm 58 sounds like pretty good going!
Happy Birthday, Giving What We Can!
edit: formatting of links
Aww, thanks Dale! If you want to see the full graph, you can check out our dashboard: https://www.givingwhatwecan.org/dashboard . The interesting change of rate at the beginning of last September doesn't actually match a sudden change of strategy. We think that it's a combination of factors: we gradually increased focus on following up with people who seemed interested in GWWC / got part way through joining, we brought in different ways to start out on a pathway to membership rather than it being all or nothing (specifically by increasing focus on Try Giving), we got a full-time Director of Community to focus on membership (Ben Clifford started at the beginning of September), and interest in joining increased following Peter Singer's TED talk at the end of May that year.
Oh nice, congratulations on making the data publicly available! I'm irrationally pleased that my chart is the same shape, though this shouldn't be a surprise, as the data did come from GWWC.
btw you need to remove the period from the link like this for it to work. Also I am concerned that the number of people currently engaged in trying giving drops so much in 2016, though impressed with your prescience!