There are many valid criticisms of the Citi Bike program, but it's a lot easier to ignore them if you can ride for free. In exchange for signing up for its email list, Citi Bike will give you a day pass on the house, which means you can forget how much you hate the Citi Bike for 24 hours.
Now we know you're thinking, "I don't want to give them my email address. They'll spam the shit out of me." Chill out. You can easily unsubscribe from the list after you've received your spoils. Or you could just give them that embarrassing email address you created when you were 13 but haven't gotten around to deleting yet. Just make sure you use the pass by April 30.