Make a resolution: Try participating in social media next year. While your site remains important, your visitors aren't only finding you through search. There's definitely enough audience ready to discover you through social media too.
Why bother? “The Internet lets all stuff fall apart in really useful ways” says David Weinberger, the author of Content Is Miscellaneous.
Your success depends on thinking more like Weinberger. All your stuff has already fallen apart, when people find you on search engines. When your content gets further disaggregated and shared through social media, that's another opportunity.