Some distributors want this to change. Dylan Marchetti, founder of theatrical distributor Variance Films, has worked with several companies on titles’ VOD releases; he calls the lack of of transparency "stunning and infuriating.

“I know filmmakers who have been surprised to receive $600 after being on VOD for six months and filmmakers who have gotten $100,000,” he said. “The surprise is not appropriate."

Some distributors suggest that it may be as simple as a fear of the unknown. "I don't think anyone wants to be the first," said Nancy Schafer, executive VP of Tribeca Enterprises, parent company of theatrical and VOD distributor Tribeca Film.

Gallagher took that chance at SXSW earlier this month when he released a document that showed the breakdown of the VOD numbers for a handful of Gravitas-released films, including a detailed numbers behind films such as "The Bill Hicks Story" as well as the narrative film "5 Star Day" and the documentaries "Billionaire" "Elephant in the Living Room," "DMT: The Spirit Molecule" and "Fat Sick & Nearly Dead."

But a lot of distributors don’t. IFC Films, which said it releases about 50 VOD titles annually, declined to make any further comment for this story. And Eamonn Bowles at Magnolia Pictures, which and pioneered the “ultraVOD”  model (i.e., films released on VOD before their theatrical dates) argues that simple number-crunching isn’t good for the business.

"It's such a simplistic abstraction," says Bowles. "It doesn't account for money spent and all the other parts of the equation. It doesn't reflect economies of scale. If we go down that reductive road, it doesn't help us. There's no context for those numbers.

"We’re not about bragging," he continues. "That's the problem with the industry, all the dick-wagging that goes on. When you start going to the lowest common denominator, it makes it harder, not easier."

Bowles also notes that the indie films’ numbers aren’t terribly attractive compared to their studio counterparts. "You don't want to be lumped in with the 'Twilights,'" he said.

Still, looking for change? Watch TV. As the VOD market matures, "data analysis will be increasingly important," Gallagher said. "And the market will demand better data to make better decisions."

As to when that moment will come, it probably will be after VOD data for TV is made public. Goerlich said he believes that TV VOD reporting will mature faster because it has to: networks rely on viewer statistics to support ad revenue. "In an advertising-supported business, they need to have more transparency," he said. "There are no hidden numbers in those businesses."

However, since movie VOD is a transaction between cable operators and film companies, there's less incentive for that information to be made public. "And going from a closed market to an open market doesn’t do anything to help the cable operators," he said.

In the meantime, filmmakers can do it for themselves. If companies won't educate filmmakers about the revenue VOD generates, Marchetti suggested that producers should share that information amongst themselves. 

"The one thing that I always preach is that filmmakers do eventually get their numbers, so the more they put that information out there, we can create a database of information," he said. "If filmmakers can say, 'This is exactly what I made,’ this will be able to help other filmmakers plan better, market better and cash-project better."

Marchetti also said that the more information there is about VOD grosses, the more theater owners might feel less threatened about theatrical and VOD day-and-date releases. "It's not necessarily an antagonistic relationship," he says.

But industry sources suggest that it's still going to take time for companies to come forward. "My philosophy," says Tribeca Film general manager Todd Green, "is that I'm not concerned with how other companies are doing. I know VOD is working for us. And when the industry is ready to share, it'll happen organically."

But when we asked Green about what kind of numbers Tribeca's top VOD success, the reality TV horror film "Grave Encounters" grossed, he replied, "I'm not going to answer that."