(updated 5/19, 12:27 PM w/ SXSW figures) If indie film, and specially the real indie side of the indie film world, were a business (it actually is, but stay with me here), we would eventually need to find out how many customers there are/were in a given time period in order to extrapolate how much $s the business generates in order to plan for the future, etc. So, one way to go about this, to figure out the shape - $s wise - of this indie film thing is to take a look at attendance at film festival. To that end, here are some notes & links. You could multiply the numbers by 10 or 20 or more (at the last film fest I went to I spent at least $50 I think) to get a rough idea about the amount of money that may get spent just through ticket purchases at several film festivals. Of course a lot more $s get spent in related expenses: travel, lodging perhaps, food, merchandise, etc. The good news for filmmakers is that there are lots of people out there who will spend money to check out indi...