Google decided to take further steps in removing doorway pages from its search results, by modifying the search engine’s algorithm.
Doorway pages, also known as jump pages or gateway pages, are used for spamdexing – they insert particular phrases with the sole purpose of getting a good rating on the search engine, and once the unsuspecting user clicks the link, they get redirected to a completely different page, most likely where the user didn't want to end up at all.
Google doesn't want those pages showing up in the search results because, as Brian White from the Google Webspam Team wrote in a blog post, they can harm the quality of the user’s search experience.
“For example, searchers might get a list of results that all go to the same site. So if a user clicks on one result, doesn't like it, and then tries the next result in the search results page and is taken to that same site that they didn't like, that's a really frustrating experience,” he writes.
“Over time, we've seen sites try to maximize their 'search footprint' without adding clear, unique value. These doorway campaigns manifest themselves as pages on a site, as a number of domains, or a combination thereof. To improve the quality of search results for our users, we’ll soon launch a ranking adjustment to better address these types of pages. Sites with large and well-established doorway campaigns might see a broad impact from this change.”
Google has also added clarifying examples to help webmasters better understand these changes, and you can check them out on this link.