FYI this is part of the reason I watch Fringe and other bubble shows I like on Hulu or another (legal, sanctioned) online streaming source.
I'm not a Nielsen family so my TV viewing isn't counted. But online, every single person that watches a show is counted.
Does this make a difference? Probably not. There is absolutely 0 stories of a show pulling a 1.4 on TV, but being "saved" because a lot of people watched it on Hulu. But I figure... it can't hurt. At least my view is COUNTED, this way.
Plus, I would imagine online viewership is not an insignificant amount of money, at this point. A little back of the envelope math:
If ~300,000 people stream each episode of Fringe, and there are four paid 30-second commercials (assuming one unpaid), that is 1.2M paid spots per episode. If those spots are sold for $30 CPM, then that is $36,000 per episode, or $792,000 for the season. Not much, but not exactly chopped liver.
& of course it is possible twice that many people stream, Hulu CPMs are $50 not $30, there are 8 paid commercials (2 per break) etc.