Readin' Archives, Findin' Links

Occasionally I have downtime at work, and I like to read the archives of my favorite blogs. Eventually I will be all caught up! Thanks to Smart Bitches, Trashy Novels (my favorite romance genre blog), I got this link http://www.guardian.co.uk/books/booksblog/2008/nov/21/bad-novels-fiction. I found it really interesting. When do you put down a "bad" book? Do you give it the 'Nancy Pearl 50'? Do you weigh it against how much you want to read the next in your pile? When is it worth continuing? I admit I wouldn't have thought that I needed to read the bad in order to recognize the good, but it's true for so much else in life and I can see why it works. Thoughts?