This blog post points out that a substantial part of Rob Thomas's Kickstarter for the Veronica Mars movie would go to making a slew of t-shirts for those who contributed $25 or more. Let's say, with labor costs, that it only costs $10 to make and ship a t-shirt -- Rob's only clearing $15.
The flip side of this, I should point out, is that cash has a multiplying effect in film financing. The hardest 10% of a film's financing is the last 10%; that's the rock so many independent films crash on. Rob doesn't have to make the movie only with Kickstarter funds. If Rob clears $2 million in his Kickstarter, he can probably get backing for another $3M, say, from people who will get paid out of the revenues of the picture -- which the Kickstarter gang won't. It's a pretty good gamble that a $5M picture will make them at least $3M, which, considering it's based on a TV show people have heard of, with a TV star, ought to be possible. (I'm making these numbers up. Maybe it's a $4M picture for $2M. Maybe it's a $10M picture for $8M.)
(Whether Warners will let him make it for only $5M, who knows. But let's assume they're sane, and see no drawback to having a creator take a dead series of theirs and turn it into the first in potentially many movies, or even another series, which they would own.)
And, of course, the Kickstarter money also proves the value of the franchise. There are rabid fans out there. If there are 45,000 people willing to pay $10 and up for schwag, how many would be willing to pay $15 to actually see the movie? How many will buy the DVD?
And, there's 45,000 people talking about the movie. There's your word of mouth campaign. 30,000 t-shirts is a lot of publicity. That's a lot of billboards
that people are paying to walk around in.
So, sure, $3M in Kickstarter funds is not the same as $3M in the bank.
On the other hand, in many ways, it is substantially better.