The timing of audience reports is a major issue for both the networks and advertisers. Data collected by people-meters is available on the morning after programs have aired. However, data collected by diary methods requires much more time to collate and analyse. Radio surveys, for example, which are still used for radio ratings in many countries, are normally only available on a quarterly basis. The time lag in reporting fails to provide advertisers with sufficient lead times to take corrective action during a campaign.