Would you pay $10,000 (€7,700) for a speaking role in a film spin-off of the cancelled TV show Veronica Mars ? You'd be playing a waiter. "The line," says Rob Thomas, the show's creator, "is 'Here is your check, sir.' "

Veronica Mars , a witty, original drama about a teenage detective solving nefarious crimes in a California high school, ended in 2007. The last episode saw Mars, played by Kristin Bell, wander into the rain with several subplots unresolved. The small but devoted fan base was very unhappy. "The most frequent question in interviews afterwards was whether there would be a movie," says Thomas.

Last week, with the support of Warner Brothers, which owns the rights, and the cast, he started a campaign on the crowdsourced fundraising website Kickstarter to raise $2 million (€1.5 million) to make a movie. In this instance, for donations of $35 fans would receive a copy of the script, an exclusive download of the finished movie and a T-shirt. For bigger donations they would get invitations to the premiere. For $400 cast members would follow them on Twitter or record personalised messages for them. For $10,000 they would get the film role.

Thomas and company reached their target in 12 hours. At the time of writing they have $3.6 million (€2.8 million). "I was completely blown away," says Thomas. "My first encounter with Kickstarter was when a friend asked me to pledge to his album. As I watched him raise $10,000 I sat there looking at it, thinking, Could we do this with Veronica Mars ? At the time the biggest Kickstarter drive ever was about $900,000 and we would have needed much more than that. I thought it was sort of crazy but we had run out of traditional paths to make the movie."

Fans flexing muscles
The Veronica Mars project is the first of its type on Kickstarter and a rare example of one with connections to a multinational corporation, but it's just the latest example of fans flexing their muscles to get more of their favourite programmes. Trekkies marched on NBC studios as long ago as 1968 to ensure the original Star Trek was renewed for a final series. More recently, fan campaigns have led to the renewal of niche shows such as Chuck, Friday Night Lights and Jericho , as well as film spin-offs for cancelled science-fiction epics such as Farscape and Serenity . Another cancelled cult favourite, Arrested Development , was recently given new life on Netflix.

Thomas has long been aware of the impact fans can have. "It's changed hugely in my 15-year television-writing career," he says. "My first job was on Dawson's Creek , and at that point we had very little idea what fans were thinking. You could see Nielsen ratings, and if you had a set tour, fans would show up. Now the internet allows an instant reaction . . . With Veronica Mars I was writing a long murder mystery. I had 22 episodes to do, and I could go on to a fan forum and get a clear idea what was working, what was not working, what clues they were following, where they thought the case was going. Things I read would definitely make me steer away from certain things or push a storyline they were responding to. It radically changed how the fans impacted on the shows. We weren't flying blind any more. We knew what they were saying."

The financial benefits of such active fandom are beginning to be understood. Henry Jenkins, author of Textual Poachers: Television Fans and Participatory Culture , argues that a small passionate audience can sometimes be better than a large passive one. "There's industry research that shows that viewers like that have greater loyalty in terms of watching a programme every week, watching it right through, and in terms of watching it online and talking about it online. And they show greater brand awareness. From an advertiser's point of view, those viewers are worth more by far than an army of casual viewers who tune in every week and don't pay as much attention to what they're watching."

Fans have even been known to target advertisers. "Fans of the series Chuck had a campaign where they went into Subway stores [one of the sponsors] across the US, bought sandwiches and wrote a message saying, 'We're here for Chuck ', " says Jenkins. "It led to Subway putting its weight behind renewing the programme for another season."

However, fans investing capital is a new phenomenon. "In the late 1980s, fans talked about putting money behind cancelled shows, but there wasn't a real way to do that," says Jenkins. "What you're seeing is a mechanism that would allow a show to appeal to fans for financial support, and a whole range of new delivery mechanisms for further episodes, whether that's iTunes, Netflix, Hulu or box sets."

Jenkins believes this allows fans to have more of an impact on culture than ever. Indeed, Thomas admits that fan-funding influences the creative process. "With a crowdfunded movie I think you have to play the hits to a certain extent. And I look forward to playing the hits. It's not going to be the Spinal Tap Jazz Odyssey version of the Veronica Mars movie. If we hadn't crowdfunded the movie would I be building it around Veronica's 10-year high-school reunion? I'm not sure, but because it is crowdfunded I know they want to see these things. I receive a constant Twitter stream of what they want to see in the movie, and it would be wrong of me to engage in a flight of fancy."

Jenkins argues that crowdfunding gives fans a lot of control. Others are less enthusiastic. Anna Martin, who is writing a PhD on fan culture at Lancaster University, feels that this kind of fan power is illusory. She argues that it's a studio's job to take risks and that it's unfair to outsource that risk to fans. " Veronica Mars fans are handing over their money so a corporation can make a product. It doesn't look like a very powerful situation to me."

Rob Thomas disagrees. He stresses that the movie would not get made under other circumstances, that the rewards for contributing are very good and that this is not fan investment so much as preselling. “There’s a mistaken impression out there that Warner Brothers is somehow holding the movie hostage until the fans cough up money,” he says. “As a creator it’s given new life to something that ended too suddenly; for fans, they’ll get to see something they would not have otherwise, and the studio has a chance of seeing some profit. I hope it’s an everyone-wins proposition.”

Others are following with interest. Since the Kickstarter campaign began, Thomas has been contacted by Bryan Fuller and Shawn Ryan, the men behind two other cancelled cult shows, Pushing Daisies and Terriers , and he suspects more will follow. "The industry is watching," he says. "All the trade mags are calling. After talking to you I'm calling the Hollywood Reporter . And I don't think Warner Brothers would have done this as a one-off. It wants to see if it works, and if it's a success it'll do it again."