I live in Boston and I ended up buying a bike to commute into work. Boston/Cambridge is great for cyclists (drivers not included). The point of Hubway is you pay for the convenience of the network. They have stations literally everywhere. And the cost of maintaining those bikes and stations is probably very high. I think I read somewhere that NYC's Hubway equivalent was losing money (even though it's partially sponsored). I'm not sure how popular their annual memberships, I suspect a lot of the revenue comes from the casual renters like tourists and working folk needing to get from point a to b quickly.