Breaking a fundraising record doesn't require a history of flying spaceships, but it doesn't hurt.

If there's one conclusion to be drawn from the not yet three-day-old Indiegogo campaign from actors Alan Tudyk and Nathan Fillion, it's that crowdfunding is a great way to measure pent-up demand for a product.

Tudyk and Fillion, who starred in Joss Whedon's short-lived but much beloved cult sci-fi TV series Firefly, shattered their fundraising target of $425,000 within hours of launching their campaign. The actors are funding a new web series based on their lives post-Firefly, which ran for 14 episodes before being cancelled in 2002.

So what market research did they do before asking the show's fans to fund their project?

"I've met fans for 12 years now, going to conventions," Tudyk told the Wall Street Journal. "I've been listening to them lament the show being cancelled, being frustrated it lasted only 14 episodes."

The new show, entitled Con Man (short for Convention Man) is based on those experiences going to sci-fi conventions and meeting fans still mourning the loss of Firefly.

As of noon on Friday, the campaign had raised more than $1.5 million from roughly 21,000 backers, breaking the record for the most funded web series ever: Spike Lee's Da Sweet Blood of Jesus, which raised just over $1.4 million in 2013.

It's not the first time TV fans have raced to resurrect a cult show show via crowdfunding. In 2013, a Kickstarter campaign for a film version of the similarly beloved series Veronica Mars hit its $2 million goal within half a day, and eventually raised $5.7 million.

So what's the lesson for entrepreneurs?

If you truly believe demand for your product exists, you might be one crowdfunding campaign away from raising the startup capital you need. Tudyk and Fillion sought $425,000 to fund the first three 10-minute episodes, but are now within striking distance of the $1.6 million "stretch goal" needed to produce 11 episodes. 

And there are still 29 days to go in the campaign.