1. A method to monitor media presented at a monitored site via a meter at the monitored site, the method comprising: comparing, at the meter, a set of site signatures generated by the meter for a first time period with a first set of reference signatures representative of reference media predicted to be presented during the first time period; in response to determining that at least a first subset of the set of site signatures matches at least a first subset of the first set of reference signatures, reporting, via the meter, metering data but not reporting the first subset of the set of site signatures, the metering data indicating that first reference media represented by the first subset of the first set of reference signatures was presented during the first time period; and in response to determining that the set of site signatures fails to match the first set of reference signatures, reporting, via the meter, the set of site signatures.