Site-wide links are
typically links
found in a footer or header of a website that appears on every page on the website. These links are considered untrustworthy by Google since these are typically from company-owned domains (not a true third-party referral) or paid link relationships. Matt Cutts adds, "We've done a good job of ignoring boilerplate, site wide links. In the last few months, we've been trying to make the point that not only is link buying like that not doing any good, we're turning the dial up to let people know that certain link spam techniques are a waste of money