Google is , by far , the largest Internet advertising agency .
Google also scans the content of emails of users of its Gmail webmail service , in order to create targeted advertising based on what people are talking about in their personal email correspondences .
Google is , by far , the largest Google     .
Google also scans the content of emails of users of its Gmail webmail service , in order to create targeted advertising based on what people are talking about in their personal email correspondences .