The present invention relates to a data sharing service system, and a method and a device for a data sharing service, and to the data sharing service in a multi-device environment. Particularly, the present invention enables a user to summarize information on content being used or to transmit data on specific content to terminal device of another party by using a messenger, so that the user can gather the contents of interested articles (or books) to manage the contents by compiling statistics and the user can easily notify the other party of the contents of the articles (or books) without requiring the user to write out the interested contents one by one when using the messenger.