For JS CS, up until recently, running email campaigns for their clients was a throwback to the analog era. Since these campaigns were sub-contracted to 3rd party publishers whose mailing lists the messages were sen to, the execution used to be a rather timeconsuming and error-prone process. From placing an email order with the publisher and combing through spreadsheets with email addresses, to having to wait, sometimes for several days, for the results before reporting back to the client.