Generally, you'll need to be regarded as an autority site. However, my understanding is that they are NOFOLLOW links, so it won't improve your page rank.
Edit the content on which you are expertise and set link in between content. It;s upto mods. they remains or delete your link.
A nice idea would be to post a article on which there are very few ones on wiki.. If your information is correct and useful, you will get a link!!
Wikipedia doesn't welcome your links, especially when you only want to post a link there. Most of the links are no follow, while little authoritive editor have do following links.
All ordinary external Wikipedia links are nofollow. Don't just take my word for it, go check any Wikipedia article. There is no need to chase Wikipedia links for SEO purposes. They might bring visitors, but they would have to be useful to the readers, otherwise they will be deleted quickly by editors. (at least in the popular topics)
I have a wikipedia page and the link to my site is a nofollow link, if you are an expert in a certain field you may be able to get a backlink from wikipedia. However, I do not think a wikipedia link has any seo benefits.
wikipedia links are nofollow for some time now. if you want to add your link there to ge some traffic, thats one thing. but if you want to get backlinks form wikipedia, then its nothing but waste of time
But the guy want to post his own link... in others content how could he post it... please let us know..
You can add your website in wikipedia if it is worth. No place for business websites in wikipedia. It is nofollow, so you will not get any advantage of PR juice.