A watchdog system for identifying failures in uniform resource locators (URLs) respective of advertized content. The system comprises a database containing at least campaign information, the at least campaign information containing at least a URL to be monitored by the watchdog system, the URL directs to advertized content; and a server connected to the database and operative to monitor the at least URL for identification of a failure in the URL providing the advertized content, and performing a corrective action for correcting the URL based on definitions in the at least campaign information.