Broken link building is a tactic that can in some cases help you bypass all that hard work. It provides you with an ‘in’ so to speak and this is how it works. You find broken links on a web page – you contact the owner and let them now that their site is pointing to non-existent content in some cases. After that, you’re in their good graces.
“Links matter. No secret there. How much they matter, wellâ€¦therein lies the secretive part of the equation. And as much as readers of this blog would love for me to slip up and say they account for N% of the equation, I wonâ€™t. The fact is, the actual value links apply varies based on other factors, so there is no solid number. Back when everyone was chasing â€œkeyword densityâ€ as a ranking objective, everyone wanted to know what the magical percentage was. Same deal â€“ it depended on a variety of factors. While keyword density has gone the way of the dodo, links continue to provide useful signals, despite the obvious spamming that happens. So letâ€™s take a quick look at some ways to build links that you should avoid.”
From Google Webmaster Central, how to apply for reconsideration if you’ve fixed your spam backlinks.
It seemed like a good idea at the time but now you’ve been pecked by the Penguin? See this video from Matt Cutts about how to tell Google you really didn’t mean to artificially inflate your inbound link count.