I gave Studio 60 a full season to win me over…
Just as DrFidelius said, the previews had better hook me or I won’t start watching. Husband won’t either - sometimes he’ll take my word for it that a show is worth watching, but usually he won’t. We don’t spend a whole lot of time together anyway in front of the TV - he usually goes upstairs at 6 PM or so so I watch primetime alone.
Books - I’ll give them maybe a chapter - but if it’s just terribly bad, a few chapters.
I’ll give a book a few paragraphs or up to a longish description. I’ll know by how the author handles preliminary descriptions whether I want to keep reading or not.
In terms of TV, I like giving it a season or two and, if people like it, I’ll get the DVD or download a bunch. I don’t watch enough TV to be able to sort through all the crap to find the two or three shows that will be worth spending hours watching.