A method performed in a personal data manager computing device for facilitating propagation of personal data, the method comprising: receiving from a personal data subscriber computing system a request for one or more personal data items stored in a secure data store communicatively coupled to the personal data manager computing device, the one or more requested personal data items representing personal information about a user; determining whether the request for the one or more personal data items is in accord with a personal data subscription associated with the personal data subscriber computing system, the personal data subscription entitling the personal data subscriber computing system to access a plurality of personal data items from the secure data store, wherein the personal data subscriber computing system obtains the personal data subscription from a remote personal data propagation service computing system; and when the request for the one or more personal data items is determined to be in accord with the personal data subscription, transmitting the one or more requested personal data items to the personal data subscriber computing system to cause the personal data subscriber computing system to initiate an electronic commerce transaction, wherein the personal data manager computing device determines whether the request is in accord with the personal data subscription associated with the personal data subscriber computing system by interacting with the remote personal data propagation service computing system to determine whether the one or more requested personal data items is one of the plurality of personal data items to which the personal data subscription associated with the personal data subscriber computing system entitles access, and wherein the personal data manager computing device is a personal computing device of the user and wherein the personal data manager computing device, the personal data subscriber computing system, and the personal data propagation service computing system are distinct and remote from one another. receiving from a personal data subscriber computing system a request for one or more personal data items stored in a secure data store communicatively coupled to the personal data manager computing device, the one or more requested personal data items representing personal information about a user; determining whether the request for the one or more personal data items is in accord with a personal data subscription associated with the personal data subscriber computing system, the personal data subscription entitling the personal data subscriber computing system to access a plurality of personal data items from the secure data store, wherein the personal data subscriber computing system obtains the personal data subscription from a remote personal data propagation service computing system; and when the request for the one or more personal data items is determined to be in accord with the personal data subscription, transmitting the one or more requested personal data items to the personal data subscriber computing system to cause the personal data subscriber computing system to initiate an electronic commerce transaction, wherein the personal data manager computing device determines whether the request is in accord with the personal data subscription associated with the personal data subscriber computing system by interacting with the remote personal data propagation service computing system to determine whether the one or more requested personal data items is one of the plurality of personal data items to which the personal data subscription associated with the personal data subscriber computing system entitles access, and wherein the personal data manager computing device is a personal computing device of the user and wherein the personal data manager computing device, the personal data subscriber computing system, and the personal data propagation service computing system are distinct and remote from one another.