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I have a very large US based website and series of European sites which are very new and therefore have very limited inherent equity. my US collegues have suggested using alternate language headers:

In my opinion this should significantly help the SEO of the new European sites. Does anyone have any experience with this tag?

Thanks for your help in advance

Before everyones pounces on this question and says "You should do your link builidng yourself" please bear in mind there are two people in my team (including myself) to manage multiple websites in 23 countries!

Does anyone have any recommendations for quality link building companies in UK or in France, Italy, Germany and Spain?

Only quality companies please! SEO agencies will be considered!