If Open Source software provides any clues, marketing is indeed a problem.

Consider 'Blair Witch Project' which cost US$ 35.000 to make, was sold for US$ 1.1 Mil., and then the company spend US$ 20-25 Mil. for marketing. And this was an awesome campaign.

"Open Water" cost US$ 500.000, was bought for US$ 2.5 Mil, and the company spend additional US$ 8 Mil. on distribution and advertising.

Box Office revenue is more closely correlated to advertising dollars spend than production dollars spend, accorindg to the presentation here: http://abovethelineproducer.blogspot.com/2011/12/hollywood-p...