Stephan Spencer is author of Google Power Search, co-author of The Art of SEO, and co-author of the upcoming Social eCommerce (due out in April 2014), all published by O'Reilly. Stephan founded Netconcepts in 1995 and grew it into a multi-national SEO agency before selling it in 2010 to search software/services agency Covario. He is the inventor of SEO technology platform GravityStream.