Last week, the bike share guide was released by the IDTP and lots of buzz online and in the bike world ensued. In the report, a few charts about bike sharing are shown, the first one, above, shows the tipping point that was reached a few years ago, and the massive growth since then. At a scale that shows the recent increase in number of bikes in bike shares, the previous growth basically looks like a flat line. That's how different the past few years have been!
A catalyst has been the launch of Velo'v and Vélib in France, but new bike shares have popped up all over and the number of stations and bikes has steadily climbed, which has helped increase usage, as the chart below shows.
There definitely seems to be a correlation between how many bikes are available and the number of trips, which makes sense. It's all about convenience: Can you find a bike when you need one? Can you drop it off at a station close to where you're going? Do you see many other bikes from the bike share riding around the city (creating social proof)? All these help keep the boom going (for example, bike-sharing in the U.S. expected to reach 37,000 bikes in 2014 (4x more than in 2012!)).
If your city has a bike share and you haven't yet tried it, I encourage you to do so. Bring some newbies with you (friends & family) for a casual ride. It's trying it the first time that is hardest. Once people are familiar with how it works, they're much more likely to ride again.