While working with film maker Phil Calderone in brainstorming sessions for the aborted second episode of his short lived web series Live Or Die, I learned quite a bit in the short time we collaborated. In my brief experience, he revealed web series are lucky to even run five or six episodes, with each running three to five minutes and two alternate endings.
He also mentioned each installment has to be funded on an individual basis, due to the fickle and unpredictable nature of the web series medium at this point. They also have to be anthologies or episodic series. Since most of them have yet develop a consistent audience or any major popularity.
Yet they are cheap to produce at a budget ranging from less than $1,000 anywhere up to $3,000. However, these costs go toward production equipment with the cast and crew often working for free to get exposure for potential film and television work. Often relying on thousands of Facebook friends and YouTube views before they get their first paid job.