The rankings below are based on the the show's rating in the 18-49 demographic and it includes delayed viewing and it has repeat broadcasts factored in. So you have to look beyond the actual numbers and also understand a little about each of the networks as well.
The third and fifth highest ranked series among genre shows, both from FOX present an interesting case study. Alcatraz ended the season ranked 30th overall and got cancelled whereas Touch ended at the 51st rung overall and got renewed. Both series started out strong yet suffered steep declines as the season progressed, though apparently Alcatraz pulled in higher numbers on delayed viewing. So why did Touch get the nod over Alcatraz? Can't quite say for sure. Maybe because Alcatraz had sunk further than Touch by the time decisions were being made for next season's schedule. Maybe Keifer Sutherland's star power trumped J.J. Abrams' name recognition. Maybe FOX execs liked Touch more. In truth, they both probably should have been cancelled based on the ratings they were pulling at the end of their runs, but apparently FOX felt Touch had more potential for a turnaround (though it is getting cast to Fridays next season).
The seventh highest ranked genre show, NBC's Grimm, was only ranked 81st overall yet it still got a renewal. But it airs on low viewership Fridays and actually performed decent there for the fourth place network. They decided to cut ties with Awake, though, which ended the season ranked 104th overall.
at this link.
Finally, there's the shows from perennial fifth place network The CW, the highest of which ranked 123rd overall. That was Vampire Diaries and it is the CW's highest rated show, so obviously it got the renewal. Supernatural (141st) and Nikita (150th) both got renewed as well. But the CW apparently felt that new series The Secret Circle did show enough life and cancelled it, even though it outperformed the latter two series. But those two air on Fridays (where ratings expectations are lower) and have been around longer, and Nikita has a strong international following. And when we're getting down to the ratings cellar where The CW reigns, we're really just splitting hairs with these numbers. Apparently the network felt stronger about its up and coming pilots than it did about keeping The Secret Circle around.
You can read more of my thoughts on each of these shows at this link, and following are the final rankings numbers from this last season:
|Overall Rank||Genre Rank||Network||Program||Status|
|16||1||ABC||ONCE UPON A TIME||Renewed|
|32||4||CBS||PERSON OF INTEREST||Renewed|
|120||10||CBS||GIFTED MAN, A||Cancelled|
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