Bikeshare is hugely popular in DC. It's expanding more into the suburbs now. They began by placing stations near Metro rail (subway) stations. I don't know about tourist usage but I know many residents use them to get around in the city where traffic is ridiculous. There was a station in my (suburban) neighborhood for a while but they removed it because the bikes there weren't being used. I never saw the need for it -- by the time I walked to the bikeshare station I was already halfway to where ever I was going so it made more sense to keep walking.

From what I've seen about NYC's bike share, the stations are all in more upscale areas.