Metered data is accumulated and is indexed within a metering database of a client according to a metering ID (MID) and a content-associated ID (KID). The client selects a particular MID and metered data in the metering database having the selected MID, and constructs a challenge based on the selected metered data and sends same to a metering service. The metering service obtains the metered data from the challenge, stores same, and constructs a response. The client receives the response including a list of KIDs of the selected metered data in the challenge, and processes the list of KIDs by, for each KID in the list, deleting the metered data from the metering database having the selected MID and the KID.