At Blue Fountain Media, we create most of the content on most of the sites we work on. That gives us the ability to choose titles, headers, content, and copy that will bring in search visitors. But many of the largest, most popular sites don't use this model at all: Yelp, LinkedIn, and Ezinearticles have all been able to rank highly on Google even though their content isn't controlled by SEOs.
Here are some of the techniques they use—the internal linking structure, the user guidelines, and the content aggregation methods they use to rank well even if they don't know what they'll rank for.
• Yelp.com's SEO has quite a pedigree: they're one of SEOMoz's clients. There's a detailed (but now obsolete) description of the SEO tricks Yelp used to optimize their site:
Essentially, what Yelp does is combine a 'directory'-style front page (with hierarchical information easily accessible to search engines) with fresh content that entices users (and means that frequently-updated pages get indexed). At the same time, Yelp used to aggressively use the nofollow tag, a technique that is not nearly as effective as it used to be.
• LinkedIn.com's SEO is designed to do one thing and one thing only: make sure they own your name on Google. To do this, they've created several alphabetical directories (which search engines can quickly rip through to gather the data they need) and a few subject-specific pages. LinkedIn also brings in links by giving people badges they can post to their sites.
• Ezinearticles' SEO stands out from the group for a couple reasons: one, the site is not as well known as LinkedIn or Yelp—and yet, you're almost guaranteed to have encountered it at some point in your life. If Yelp is for places, and LinkedIn is for people, Ezine is for "Misc."
They use some standard SEO techniques—detailed category views, 'related-articles' links to give search engines contextual clues, and a front page full of random articles so something five clicks away from the homepage will still get noticed by search engines. But the most important thing they do is require quality: they edit articles to reject grammatical errors and tone down salesly language, and the result is that you can't help but write something helpful if you're using Ezine. They could operate the site as a loophole in search engines' ranking algorithms, but instead they closed the loophole and created a source of reasonably high-quality information.
As we prepare to launch a very exciting user-generated site (with a great chance to change the industry and a decent chance to change the world), we're doing everything we can to learn how other user-generated sites succeed.