3. The method as recited in claim 1 , further comprising: determining an overall meaning of the respective electronic transmission in an anonymous non-identifying manner without retaining contents of the respective electronic transmission.
1. A method comprising: accessing one or more electronic transmissions transmitted from a client computing device or ready for transmission from the client computing device; for respective electronic transmissions of the one or more electronic transmissions: scanning content of the respective electronic transmission to identify one or more keywords included in an advertising data structure; selecting one or more advertisements for insertion into the respective electronic transmission based on relationships stored in the advertising data structure, wherein the stored relationships indicate associations between the identified one or more keywords in the respective electronic transmission and the selected one or more advertisements; inserting the selected one or more advertisements into the respective electronic transmission, wherein inserting the selected one or more advertisements comprises changing at least one display characteristic of one or more words already included in a message body or subject line of the respective electronic transmission; and initiating transmission of the respective electronic transmission to one or more intended recipients.