not as common as ordering an entire season but lots of mid-season launches are 6-10 episode orders. Also, they don't put out the entire season before feedback, hence many mid-season cancelations. I think this is a hold-over from when the airtime had a lot of value, where as now the broadcast bandwidth for your typical cable timeslot is effectively zero and the content is actually valuable. Async, on-demand consumption has pretty much killed the concept of prime time...