Yeah, empty docks are a big problem for me when the weather is pleasant, because (like a typical tech worker) I get in pretty late. It's not uncommon for me to have to walk almost half of my commute in the morning in the summer until I find a station with a bike. And sometimes the nearest stations near my apartment are full at night too, if I get home later.

That's actually why I love commuting in the winter the most. I never have any problem getting bikes at the closest station when it's below freezing.

I dream of them adding enough stations and enough bikes to the point where this is no longer a problem. They do some rebalancing, which helps, but it isn't consistent enough to rely on.

Several reasons, in descending order of importance:

a) I don't have anywhere to store a bike in my apartment. My work has a bike room, but it's less convenient to use than the Citibike station right on the street. My roommate used to keep her bike locked up on the street at our apartment, and it got stolen only a few months after she'd gotten it.

b) Even if I owned my own bike, I might still have Citibike anyway, because there are trips that I make (usually at night) where I use Citibike to go meet up with people somewhere, and then we continue traveling using other modes of transit, such as cab or subway. Being able to leave a Citibike behind is really nice.

c) Maintenance. I don't have to worry about it at all beyond pressing a button when returning a Citibike that's misbehaving. There's a non-trivial amount of maintenance involved in keeping a commuter bike running (especially one that's ridden in rain and snow), and I just don't have to worry about it at all.

Most of the people I know who use CitiBike use it as one leg of their commute. One of my coworkers, for example, takes the PATH in from New Jersey then bikes to the office from there.

In these cases you could buy a bike and leave it in the city, but there's a very very serious risk of bike theft. It's easier to pay for the CitiBike membership and not have to worry about it.

I take BABS (Bay Area Bike Share), the equivalent system in and around San Francisco, which is similar in nature to the Citi Bikes program. In fact they use the same bike model. I have 2 bikes of my own, but it's more convenient to hop on any random bike and drop it off without having to bring a lock. Sometimes I also want to go somewhere to meet people and then we walk or take the train/bus back. I live in SoMa, where most stations are, and I rarely walk anywhere these days since BABS is more convenient, and more fun. The only complaints are that all stations are around SoMa and the financial district (being addressed soon) and that the bikes are too heavy, about 40lbs which is a problem in a hilly city.

In New York, no one has space to keep a bike in their apartment. Okay, that's a bit of an exaggeration, but it is an issue. It's certainly an issue for many here in Boston, where Hubway bikes are popular. I ride my own bike to work, but I have a shed I can keep it in.

I don't think they take bikes off the road during the winter, or at least, they don't take enough off the road to be noticeable relative to the decreased number of trips that other people are taking. Winter is prime commuting for me because I can always get a bike at the nearest stations. The stations are undersized for peak summer commuting traffic, but fine for winter.