Each week the index lists the top 25 “stickiest” 30-, 60-, and 120-minute programmes based on anonymous viewing data collected through Rentrak’s partnership with AT&T’s u-Verse – a combined internet, TV and telephony service.

Programmes are rankedaccording to the average percentage of the programme viewed, divided by the average percentage viewed for all programmes of the same duration.

The first week’s data, for example, showed that President Obama’s address to the joint session of Congress on the issue of healthcare reform was one of the “stickiest” programmes across multiple networks, but while Fox News did not deliver the highest ratings for the address, viewers tuning in to that channel were more likely to view the entire address.

Rentrak’s recently appointed chief research officer Bruce Goerlich (pictured) said: “The correlation of ratings to engagement is an integral component in determining how ‘tuned in’ viewers are when they are watching their favourite programmes.”