I concur, most of the job offers I get are relevant and some of the big companies' internal recruiters contact me via LinkedIn: Google, Facebook, Amazon. It may

I concur, most of the job offers I get are relevant and some of the big companies' internal recruiters contact me via LinkedIn: Google, Facebook, Amazon. It may not be perfect but it's far from useless. My impression is that it allows skilled recruiters to make solid connections and lookups. Poor recruiters will always be poor matchers and spam folks.