From the brief discussion with my friend, while we can only find a few very good reasons why wikipedia in google search engine. To understand it I tried to search the keyword "seo" in google.co.id, and the results you can see the picture below:
The figure above shows that the search results for keyword "seo", Wikipedia was in the first position. You can try to find other keywords, and can see the results. Wikipedia does have so many pages that rank high in SERPs. Here bebarapa reasons why these sites often appear on page 1 Google
- Wikipedia use nofollow and have anchor text as a link internal pages. We can see that a lot of anchor tex in each content they serve.
- The site has content that bekualitas so many people liked. Here proves that content is king. Quality content to make visitors comfortable and in the end they need to visit this site again. This for me is the main reason about wikipedia seo secrets to become a successful site.
- Have a Pagerank 9.