Matt says, if your site is polish and you provide a site wide link to an English website with anchor text “Rent Cheap Apartments” then it would be considered spammy to the user as well as Google. These are the sort of activities which needs to be avoided. Many webmasters are engaged in the practice of acquiring irrelevant site wide links to their website just for the sake of increasing their overall backlink count. But, this sort of strategy would not work and might go totally negative, especially when Penguin is roaming around.
What Google Does?
Google compresses the site wide links and counts all the links as one link.
Are Site Wide Links Bad?
No, it is not bad as long as it is helping the user but when it becomes irrelevant then it faces manual action by Google. For more help, watch the latest video by Matt Cutts on “How does Google consider site-wide backlinks?“.
Also See:-
Google Human Quality Raters Do Not Influence A Website Ranking Directly
Google Now Cards
Google Expands Knowledge Graph
Google Disavow Links Tool
Query Highlighting on Google
How to Create Backlinks That Google Loves
Google to Take Action Against Spammy Guest Blogging
