I don't think any of the answers fit for me. I keep facebook open all the time, but don't really check very often. Only periodically when checking rss and such stuff or when I'm really bored.
I'd recommend, over the next week, that you check how much time was spent with facebook (even if its passive, you may be checking into the screen every half hour) I'm not trying to be negative, but I suspect that number may be higher than you think.
I checked `1 hour per week` but actually I have my Facebook IM hooked up to my Adium IM client (along with 8 other services) - and I haven’t intentionally logged out of that in years. Heck I leave that on when I go on vacation and won’t be checking it for 2 weeks.
So is this poll about Facebook service usage, or personal time knowingly interacting with Facebook? The answers for me are quite different.