That depends on what you count as success, I suppose.

Boise GreenBike expansion will bring bike sharing to parks | Idaho Statesman

The system is expanding, so that's one good sign. However, only 24% of revenue came from user fees, so if the measure is making money, it's not doing so well. They have 7300 members, and had 16,049 rides, May through September. I don't know if that counts as success for Boise. 16000 rides in five months of peak season amounts to fewer rides than in a single day in the dead of winter in New York.

One thing that might be telling though is that they concluded that many of the rides were for recreation, and by people from out of town. That's the opposite of New York, where the bulk of trips are by New Yorkers, with annual memberships, to go places, rather than tourists taking joy rides. So, if the goal was to provide an alternative form of transportation for Boiseans to get around town, and reduce driving, that doesn't make it sound like it's had much of an impact. People will ride for fun, but not if they actually have to get somewhere.

Is this success or failure? I have no idea. But I'm willing to suppose that Boise's better off with bike share than without.

Anyway, just some musing based on the little bit you can glean from one article.