It frequently suffers from what I'll call "clipping", after the audio processing phenomenon: a situation wherein a given bike station is either full or empty, thus restricting the stations available to cyclists either returning or renting a bike.
Tel-o-Fun control clipping with a blue-collar fleet of trailer-towing pickup trucks, transporting dozens of bikes from the most frequented destinations to the most frequented departure points, working to reverse the effects of the its customers' routes.
I maintain that clipping could better be avoided through an incentive system, where customers receive a reward for avoiding actions which induce clipping. For their convenience, customers embarking on a journey could query the incentive database for rewards offered at the rental stations near their pedestrian starting point and end point, and thus maximize their reward.