What is off-page SEO?
There are practically 2 schools of SEO, namely on-page SEO and off-page SEO. On-page SEO is the widely accepted practices that utilize semantic markup to emphasize niche keywords to search engines for better rankings, while off-page SEO is basically link building strategies and 'anchor text' enhancement valued over on-page SEO, alleging that search engines look off-site SEO as a much more important factor than on-site SEO and good link structure yields more than just good content.
Efforts for good off-page SEO can be put as in one phrase : making as many related high-PR websites link to your site on a well optimized related page with good anchor text as possible. However, some other factors that may be analyzed by SEs include TLD of the linking site(be it .gov, .org, .edu or other), IP address of the linking site, and number of outbound links on the linking page.
So I suggest you not only markup your on-site content really good, but also try to get SEO-friendly backlinks that have the anchor text optimized on any opportunity you can.