All of you must be aware till now regarding the Wikipedia Site that, all the outbound links from this site are “NOFOLLOW” and thus have no impact on the ranking of your websites. This action has affected the ranking of various sites as the search engine web crawlers are not following these links and as a result there is no benefit for the particular site’s PageRank in Google.
Wikipedia is a free internet encyclopedia, having almost any information that you are looking for and is available in various languages. It is formed and maintained collectively by different volunteers around the world. Wikipedia has become one of the best sites that have huge traffic from search engine.
Wikipedia has now implemented a major change by making their website less interesting to the spammers by giving the nofollow tag to all the URL’s that are external links and pointing to some other destination other than en.wikipedia.org.
The reason behind making external links as NoFollow is may be to prevent spammers from using PageRank of Wikipedia for their own benefit as they can redirect some of the Wikipedia’s external links to their own site which are considered as spam sites.
Any link ascribed as NoFollow link has no influence on the ranking of your site in the search engine’s index even if your content is very good. The intention of Wikipedia behind taking this action is may be to reduce the efficacy of particular types of search engine spamming and to improve the overall quality of search engines index but because of some spammy actions of few people, penalizing everyone is not at all a good idea.
They should think again and withdraw their decision because the results of this action are not good for many innocent individuals who are delivering quality content, the details of which get supplemented by Wikipedia contributors which in turn show your site appearing after Wikipedia in search results and you may get very less or even no traffic and on the other hand Wikipedia gets to enjoy all the benefits of your hard work.