A method comprising: determining a content-transmission delay between a content-distribution system and a content-presentation device ; using at least the determined content-transmission delay to select, from among a plurality of reference fingerprint data sets received from the content-distribution system , a reference fingerprint data set that corresponds to the determined content-transmission delay, wherein using at least the determined content-transmission delay to select a reference fingerprint data set comprises: accessing mapping data that maps each content-transmission delay of a plurality of content-transmission delays to a respective reference fingerprint data set of the plurality of reference fingerprint data sets, and using the mapping data as a basis to select the reference fingerprint data set that the mapping data maps to the determined content-transmission delay; and transmitting to the content-presentation device , the selected reference fingerprint data set that corresponds to the determined content-transmission delay to facilitate the content-presentation device detecting a match between query fingerprint data representing content received by the content-presentation device and at least a portion of reference fingerprint data in the transmitted reference fingerprint data set, wherein determining the content-transmission delay between the content-distribution system and the content-presentation device comprises determining the content-transmission delay as a difference between a transmission-time stamp of content transmitted by the content-distribution system and a receipt-time stamp of the same content received by the content-presentation device . determining a content-transmission delay between a content-distribution system and a content-presentation device ; using at least the determined content-transmission delay to select, from among a plurality of reference fingerprint data sets received from the content-distribution system , a reference fingerprint data set that corresponds to the determined content-transmission delay, wherein using at least the determined content-transmission delay to select a reference fingerprint data set comprises: accessing mapping data that maps each content-transmission delay of a plurality of content-transmission delays to a respective reference fingerprint data set of the plurality of reference fingerprint data sets, and using the mapping data as a basis to select the reference fingerprint data set that the mapping data maps to the determined content-transmission delay; and accessing mapping data that maps each content-transmission delay of a plurality of content-transmission delays to a respective reference fingerprint data set of the plurality of reference fingerprint data sets, and using the mapping data as a basis to select the reference fingerprint data set that the mapping data maps to the determined content-transmission delay; and transmitting to the content-presentation device , the selected reference fingerprint data set that corresponds to the determined content-transmission delay to facilitate the content-presentation device detecting a match between query fingerprint data representing content received by the content-presentation device and at least a portion of reference fingerprint data in the transmitted reference fingerprint data set, wherein determining the content-transmission delay between the content-distribution system and the content-presentation device comprises determining the content-transmission delay as a difference between a transmission-time stamp of content transmitted by the content-distribution system and a receipt-time stamp of the same content received by the content-presentation device . <EOS>