Wikipedia can boost traffic for the site. You can get in through, create account, sign in, post quality content and get in at external link.
Wikipedia no longer any good for boosting your search engine rankings, but still good for getting a decent amount of traffic. The difficulty is getting your site to stay on there. It's not only the editors of Wikipedia that can remove your link, but also your competitors. So even if your site is a top quality site, it could still be removed by one of your competitors.
careful on how many ads are on any link you submit. I've had great articles that belonged there, not spammy at all, that got turned down because there was too much "commercial interest" on the page.