GregLindahl - 4:13 am on Nov 20, 2011 (gmt 0)

blekko's crawl is smaller than some, and we prioritize it to websites and webpages we think are more important. This might be excluding many of the backlinks for some websites, or have only a small effect for others. Also, keep in mind that the backlink count is approximate; it is only accurate to +- 50% or so.