As Wikipedia introduced nofollow tags in early 2007, search engines ranking shouldn’t be influenced by Wikipedia anymore, but nothing is more true. Wikipedia proves to be a useful tool for SEO, so let’s introduce the ‘content scrapers’.
These so called content scrapers, like Answers.com to name one of the most famous, scrape Wikipedia to collect content and publish it in their search results. The content scraped by such websites remains dofollow material and therefore adds value to your SEO as they influence search engine rankings. You got it, providing you can get your link on Wikipedia for long enough time, your traffic might skyrocket if your content get’s ‘scraped’.
If your content would be scraped by black hat companies, Google should be able to see your link was only a result of your content in Wikipedia, not because you operate in some dirty dark corner of the web.
Moreover, getting an external link on a average popular Wikipedia is something you really want to do. These external links get a respectful amount of clicks and the more people to see your link, the greater the chance they backlink to it. Wikipedia still attracts a lot of Google traffic, despite it not being ranked number 1 anymore for about every topic like in the old days.
You understand the importance of Wikipedia links, but how do you get them? This is slightly more difficult, not to say incredible hard. One way to get into Wikipedia is to fill in missing citations gaps. These are gaps, left open for users to fill in a link that refers to the correct citation. Now you could try to set up a site with content dealing with the same issue. If the quality is acceptable Wiki will accept you as a credible citation link.
Finally you could also try to manufacture a new Wikipedia page that is highly relevant to an existing page. You can then link from an existing Wikipedia page to the newly constructed page in which you have added your external link. Don’t try to ‘spam’ Wikipedia though; once you are blacklisted things might go horribly wrong for you and your SEO efforts.