A Techcrunch article plus a Beyond the Search Box live event both confirm that Blekko is now blocking certain “content farms” including Demand Media’s eHow. Here is a list of sites Blekko deams content farms that they have banned:
Clearly Blekko is missing some of the big content farms, but an interesting thing I’ve noticed is that searches for “How to ___” on Blekko suffer because of it. Site-wide bans don’t seem to be the answer as there are some decent results from some of those sites that now leave Blekko stuffed with smaller site garbage content or no content.
Here’s an example, “How to make a teeter totter”: