The intriguing aspect of Hubway’s bike sharing expansion in Boston on Monday is the fact that Hubway doesn’t want its users to take the bikes for more than 30 minutes. In fact, after the first 30 minutes, you’re metered and taking the bike for six hours will run you an egregious $100. Hubway is defining how it wants its products shared—basically for short commuting trips and not for an afternoon ride along the Charles River. The company is building out transportation infrastructure. The expansion will bring the number of bikes to over a thousand at 61 stations with an annual membership cost of $85. There are other bike sharing startups like Spinlister that are targeting the peer-to-peer rent a bike for the day from your neighbor market, and it’s always interesting to me to see how smart share economy companies learn how to be clear on their market and how sharing should occur. I like bike sharing because the shared asset is relatively inexpensive for the startups (unlike cars, for example), and it lends itself well to an organized, centralized share model where one company like Hubway can create a stable, available amount of bikes, constantly matching supply with demand.