Abstract: The presently disclosed subject matter includes, inter alia, a system and method of associating between a media source advertizing a given app and a respective app event of the given app. information indicative of an app event of the given app executed by a given device is received and data elements characterizing the given device and generating a fingerprint identifying the given device are obtained. The generated fingerprint is compared with at least one other previously generated fingerprint and based on the result of this comparison it is determined whether both fingerprints identify the same device.