The Google Penguin Update is now three years old (hat tip to Barry Schwartz for keeping tabs on the "holiday"). The update has been the bane of many SEOs' and webmasters' existence for all this time, and things really haven't gotten a whole lot better for some of them, despite promises from Google.
The reason the update exists - to fight webspam - is important, and it's certainly a problem that needed to be addressed in the search results, but there's no consensus on how well it's been executed, and a great deal of frustration has lingered, largely due to how hard it can be to recover from getting hit by the update, even when the necessary changes have been made to a site.
The reason it is so hard to recover is that Google refreshes Penguin so infrequently. Affected sites must wait until Google releases Penguin again before they can recover, and that could take months. If you're trying to run a business and rely on Google for traffic, good luck with that.
The last Penguin update happened in October, with Google making some adjustments to it over the following couple months, but that's it. We're now nearly a third of the way through the year, and nothing so far. In December, Google indicated that the Penguin update would probably just continue indefinitely. That came after Google said the latest Penguin would be a "delight" because it would update more frequently.
In a recent Webmaster hangout, Google's John Mueller commented that he doesn't think either Panda or Penguin are currently updating data regularly. So much for that.
A few months ago, we had a conversation with link expert Eric Ward about the evolution of links and link building. Asked about how linking has changed compared to the pre-Penguin area, he said, "“Once Google aimed its scope at backlink profiles, and more specifically what it considered to be unnatural backlink profiles, it was truly a game changer. For the first time the links pointing to your site could end up hurting you rather than helping you or simply being ignored. The impact of that change cannot be underestimated.”
Image via Wikimedia Commons