The anecdotal evidence is that most web series will shut down, because they don't make money and the producers/directors run out of cash, so they don't end well. That said, many do it because they enjoy the craft and they get their names and credits out there, so it wouldn't be a total loss. Perhaps a good approach would be to tell the cast and crew that they will be doing a limited series, say five episodes of half hour each, but don't expect anything.
I am approaching the industry as a writer, and I've also been wondering if I should do some low-budget filming of the scenes, to get inspiration and ideas as to how my story should unfold.
I have a half-written script that was reviewed by a very respected writer. This was my first attempt to write a script. The writer surprised me that it was a very good script, much darker than she would write, but said it's good. But my personal life interfered with the project. I have been a producer on a few of the episodes of a series a few years ago. At this time, I am creating, producing a podcast on a Psychic Medium. Which is myself.
I'm working on a web series myself right now. While it's true that most fail, there are also some big success stories out there. I think it comes down to a few things.
My least favorite part of filmmaking is probably the most important skill when approaching a youtube series. That part is business. Youtube is attractive as a marketplace for a number of solid reasons, but cash output isn't one of them. You are basically earning 1 cent on the dollar vs something like Netflix, and you need to plan accordingly.
What this really means is that to make your project financially self sustaining, you need a concept, and an execution pipeline that lends itself to generating a very high volume of views. For example, if I launch my project, and 1 million people a month watch it, we will be out of business in no time. That volume would generate maybe 2-3 grand maximum monthly, which isn't enough to hire even one qualified person to help, much less sustain interest across a team.
None of this is meant to be discouraging, but it's helpful to understand the realities of youtube when creating your plan.
Second, it's significant that you look at supply and demand for the type of series you're producing. I'll give an example of a project I cancelled after such research. I wanted to make some CGI original shorts in Vray and max, and did the research. I went around youtube looking at what was out there, and paying special attention to view counts, subs, ad placement, etc. It looked like if I spent 60k and 6 months of my life producing one, I could get back about $700.
I used to get a lot of negative comments about this kind of thing, so I'll just address it now. People say making a film or artwork isn't about the money. I agree, I'm in this for the art, which I love. You'll often hear me talk about money, but it's not because I care about it. The reason that you need to constantly care about profit and ROI, is so that you can keep making art. I can tell you from experience that if you don't design this project to make money, you'll be filming the next one alone in a shoebox with a gopro.
Third, think about the level of quality you can achieve vs the market. Something really special in a low art form is probably going to get a better result than overextending into an area where you can't effectively compete. The best claymation short is likely a better product than an Avengers knock off with your brother as Iron Man.
Lastly, you need to consider how to advertise your product. For the effort you put into an entertainment product to be rewarded, people have to hear about it, and that's become increasingly difficult to achieve without a budget. I would say nearly impossible. If you have something outstanding, maybe it could go viral from a facebook share, but it would be better not to make plans based on getting lucky. Lower cost options include many hours of social networking, such as interacting with people on forums or social media.