Why might a page with bad backlinks links be ranking highly?

Matt's answer:

Today’s question comes from Idaho. The question is, “I’ve seen multiple websites that appear in the number one spot for various keywords, whose backlink profiles are pretty low quality, like lower quality blog pages. Why wouldn’t Penguin have moved these sites further down in rankings?” Good question. So there’s a lot of possible reasons. One is Penguin is geared for certain types of spam, but it’s not geared for every type of spam. For example, it doesn’t help with hacked sites. So if a site is being propelled up the rankings on the basis of illegal hacking of sites, that’s not something that Penguin attempts to tackle. There are other algorithms that try to tackle that. The simplest explanation might just be that we don’t want that to rank, but the algorithms haven’t gotten good enough yet. And we need to make sure that the things get better. And if that’s the case, we’re happy to get spam reports. Or if you want to show up on a our Webmaster forum and say, hey, here’s a site that doesn’t look it like it should be ranking, we’re happy to hear feedback like that. The other thing could be that unless you were the site owner, Google doesn’t give you all of the links that we know of. So you might be getting the links from some other source. And you might not get a complete or exhaustive list of links in that case. So you might be seeing some of the lower page rank links or links that look a little spammy. But it could be the case that there are some good links. Maybe the site has a link from CNN, a link from the “New York Times,” a link from the “New Yorker,” a link from the “Chicago Tribune.” And if that link gets missed in the report that you see, then you might look like, oh, well, a lot of these links are not as high quality. But you didn’t realize, oh, there were a few high quality links that you weren’t seeing. So it can be a lot of different reasons. And again, sometimes, you’re doing queries that are based on the content of the page more so than links. So it can vary a lot based whether you’re in the head, whether you’re in the tail– all sorts of different factors. But if you see something that you think might be link spamming or have a really low quality profile and it’s ranking higher than you think it should, especially if it looks pretty egregious or pretty unhappy, feel free to show up in the Webmaster forum or even do a blog post about that. We read the SEO blogs. And when people say, hey, here’s a site that doesn’t look like it should be ranking where it is, there are some SEOs who don’t like that, because they don’t want to have people blow the whistle. But that’s the sort of stuff where we really enjoy getting those data points and thinking about, OK, did the algorithm miss something? Do we need to improve anything in the next iteration? And hopefully, over time, we’ll just continue to find more and more of those sorts of sites and return higher quality sites instead.

by Matt Cutts - Google's Head of Search Quality Team

Original video: