There are a lot of questions about good or bad backlinks, about the quantity and so on. Matt Cutts wants to tell you why a page with bad backlinks links might be ranking highly. I hope it will help you to make "right" backlinks)
How about: Why would a site with exact match domain and nothing but 5 pages of crappy content (that hasn't been updated in almost a year) still be ranking above authority sites?
Good answer, there are many reasons why a low backlink profile site rank higher, of course, Google is working towards this..