A method implemented using one or more processors, comprising: executing an automated assistant at least in part on one or more computing devices; processing one or more sensor signals generated by one or more hardware sensors integral with one or more of the computing devices; based on the processing, identifying one or more distinguishing attributes of a user within range of the one or more hardware sensors; based on the one or more distinguishing attributes, analyzing historical interaction data to identify one or more prior human-to-computer dialog sessions in which the user exchanged dialog with the automated assistant using one or more of the computing devices, wherein human-to-computer dialog sessions are differentiated by at least one of: passage of time between sessions, change of user context between sessions, detection of one or more intervening interactions between the user and a client device other than dialog between the user and the automated assistant, locking/sleeping of the client device between sessions, or change of client devices used to interface with one or more instances of the automated assistant; based on the identified one or more prior human-to-computer dialog sessions, determining that the user satisfies an automated assistant enrollment criterion, wherein the automated assistant enrollment criterion comprises a threshold number of human-to-computer dialog sessions between the user and the automated assistant using one or more of the computing devices; and in response to determining that the user satisfies the automated assistant enrollment criterion, engaging in a human-to-computer dialog enrollment routine in which the user is solicited to enroll with the automated assistant, wherein enrollment by the user includes storing an identity of the user in one or more databases in association with data indicative of one or more of the distinguishing attributes of the user, wherein enrollment by the user unlocks one or more features of the automated assistant that were unavailable to the user prior to enrollment. executing an automated assistant at least in part on one or more computing devices; processing one or more sensor signals generated by one or more hardware sensors integral with one or more of the computing devices; based on the processing, identifying one or more distinguishing attributes of a user within range of the one or more hardware sensors; based on the one or more distinguishing attributes, analyzing historical interaction data to identify one or more prior human-to-computer dialog sessions in which the user exchanged dialog with the automated assistant using one or more of the computing devices, wherein human-to-computer dialog sessions are differentiated by at least one of: passage of time between sessions, change of user context between sessions, detection of one or more intervening interactions between the user and a client device other than dialog between the user and the automated assistant, locking/sleeping of the client device between sessions, or change of client devices used to interface with one or more instances of the automated assistant; passage of time between sessions, change of user context between sessions, detection of one or more intervening interactions between the user and a client device other than dialog between the user and the automated assistant, locking/sleeping of the client device between sessions, or change of client devices used to interface with one or more instances of the automated assistant; based on the identified one or more prior human-to-computer dialog sessions, determining that the user satisfies an automated assistant enrollment criterion, wherein the automated assistant enrollment criterion comprises a threshold number of human-to-computer dialog sessions between the user and the automated assistant using one or more of the computing devices; and in response to determining that the user satisfies the automated assistant enrollment criterion, engaging in a human-to-computer dialog enrollment routine in which the user is solicited to enroll with the automated assistant, wherein enrollment by the user includes storing an identity of the user in one or more databases in association with data indicative of one or more of the distinguishing attributes of the user, wherein enrollment by the user unlocks one or more features of the automated assistant that were unavailable to the user prior to enrollment.