1. The site rewrote content on 200 out of 240 core pages.
2. They had been using their blog like an advertising feed. They took some time to survey their market (social listening!) and identified areas where there was an information gap. They wrote new blog articles that directly addressed those holes - and have been getting natural backlinks for those new blog articles.
3. They moved content to begin higher on the page, by shrinking an oversize graphic header.
4. They improved interlinking within the site.