If you want to avoid Google's Penguin update (or recover from it), you're going to have to make sure your site falls in line with Google's quality guidelines. We've been posting various articles on these guidelines, such as:
One of Google's guidelines is: "Avoid 'doorway' pages created just for search engines, or other 'cookie cutter' approaches such as affiliate programs with little or no original content."
So, let's look at exactly what Google has to say about doorway pages (from Google's help center):
Doorway pages are typically large sets of poor-quality pages where each page is optimized for a specific keyword or phrase. In many cases, doorway pages are written to rank for a particular phrase and then funnel users to a single destination.
Whether deployed across many domains or established within one domain, doorway pages tend to frustrate users, and are in violation of our Webmaster Guidelines.
Google's aim is to give our users the most valuable and relevant search results. Therefore, we frown on practices that are designed to manipulate search engines and deceive users by directing them to sites other than the ones they selected, and that provide content solely for the benefit of search engines. Google may take action on doorway sites and other sites making use of these deceptive practice, including removing these sites from the Google index.
Google's Matt Cutts recently posted a video confirming that Google doesn't consider tweets from Twitter accounts that post every article from a site to be doorway pages.
It might seem strange that someone would even ask about that:
@mattcutts Someone actually asked that?
@AnnieCushing *shrug* I can't help what people ask.
...but, as Cutts has suggested more than once in recent memory, people shouldn't have to be SEO experts or worry too much about SEO to still be found in Google, if the quality and relevance is there.
Also, as Google has admitted in the past, no algorithm is perfect, and when they launch a major update that impacts a lot of sites, webmasters who don't know what they did wrong (if in fact they did do something wrong) are looking for any possible thing that Google's imperfect algorithm might have found questionable.
They say, "There's no such thing as a stupid question."
If it were all so simple, Cutts wouldn't have any reason to record endless Webmaster Help videos.
Anyhow, Google views doorway pages as those who are deceptively leading users to low quality specifically-optimized pages, and that's what you want to avoid doing. Just don't use pages designed to take users to places they're not trying to go. That's where they'll get you.
In that particular guideline, Google says to avoid appoaches with "little or no original content." That's an important thing to consider, as well. Whereas Penguin is designed to target sites violating the quality guidelines, this could get you in trouble there, but it could also get you in trouble with the ever-refreshing Panda update (2 refreshes in April alone), which is focused specifically on content quality.
Google actually has a help center article specifically defining "little or no original content," where the company says, "One of the most important steps in improving your site's ranking in Google search results is to ensure that it contains plenty of rich information that includes relevant keywords, used appropriately, that indicate the subject matter of your content."
"However, some webmasters attempt to improve their page's ranking and attract visitors by creating pages with many words but little or no authentic content," Google adds. "Google will take action against domains that try to rank more highly by just showing scraped or other auto-generated pages that don't add any value to users. "
Google goes on to give examples as being: thin affiliate sites (noting that being an affiliate is no problem as long as there's added value), doorway pages, auto-generated content and scraped content.
Here's a good piece of advice Cutts gave on his personal blog back in 2005: "Do not hire an assclown SEO that makes doorway pages with sneaky redirects."
If someone came to you and said “I want to rent out your mail server. I’d like to send out some emails from your server, and I’ll give you $N to do it,” you’d be suspicious and probably say no–unless you wanted your mail server to end up on email blacklists. In the same way, if someone comes to you and says “I’ll give you $N to rent subdomains, subdirectories, or pages from you. Just link to my doorway pages from your content,” I would recommend to say no as well. It can affect the reputation of your domain if you host doorway pages for someone else and then that other person creates spam on the pages on your domain.
About a year and a half ago, Webmaster Tools started sending out notices about doorway pages.
Image: Batman Returns (Warner Bros.)