Official Google Webmaster Central Blog: Dealing with low-quality backlinks

Official Google Webmaster Central Blog: Dealing with low-quality backlinks: "If you run into some uncooperative site owners, however, don't fret for too long. Instead, focus on things that are under your control. Generally, you as a webmaster don't have much control over things like who links to your site. You do, however, have control over many other factors that influence indexing and ranking. Organize your content; do a mini-usability study with family or friends. Ask for a site review in your favorite webmaster forums. Use a website testing tool to figure out what gets you the most readers, or the biggest sales. Take inspiration from your favorite sites, or your competitors—what do they do well? What makes you want to keep coming back to their sites, or share them with your friends? What can you learn from them? Time spent on any of these activities is likely to have a larger impact on your site's overall performance than time spent trying to hunt down and remove every last questionable backlink.