Dr. Horrible tops the iTunes download chartsProof of concept? Joss Whedon spent around the “low six figures” out of his own pocket to shoot Dr. Horrible’s Sing-Along Blog, and after a whirlwind launch the summer sitebuster could bank over $2.6 million, according to some number crunching by Jeffrey McManus. McManus estimates that number assuming one million iTunes downloads of the series at $3.59 each, after Apple’s share (10%) of the $3.99 sale price. With the show already dominating the top of the iTunes TV downloads chart, this very well could be a possibility.

Whedon himself commented on his blog, confirming that “the guestimates were not far off, as far as I noticed.” He added, “This was a sensible article on a subject that will, if we beret-wearing artistes have our way, will matter very much.”

To get an idea of how many were able to watch it during its 5-day free viewing period at the DrHorrible.com site, here are the initial Hulu view counts by Act: (courtesy of David Sarno at the LA Times)

Act One: 1,149,846
Act Two: 625,552
Act Three: 427,785

All this further turns heads in the industry, as Hollywood is starting to notice that top name talent like Joss Whedon, who admittedly has a considerable and loyal following, can self-distribute original content outside of the traditional studio system. As for Dr. Horrible – we’ll be looking forward to the sequel.