Brian Jacquet, Director of Marketing for Roku, discusses who is using their product and how they got to 1 Billion views and 11 hours per week of playing time per device, while speaking at the Broadband Unlimited Conference at CES 2011.  Interestingly, their demographic tends to be older and less geek-like than the typical over-the-top video viewer. He also suggests that sales have increased as awareness of over-the-top video to the television has increased.

[Note: the quality level of this particular video isn't the best, as it was filmed from the moderator's perspective with a handheld Kodak Zi8 camera using its internal microphone.  Unfortunately, I didn't capture more of this insightful panel].