NEW YORK: As fewer people tune into broadcast TV, the US networks are under increasing pressure to demonstrate that marketing dollars are well spent during their shows' commercial breaks.

To this end ABC is launching an Advertising Value Index which will furnish marketers with detailed data about viewers, from their income levels to how long they tune-in to commercials.

The Walt Disney Company-owned network claims that AVI will enable advertisers to choose the criteria they are interested in, weigh factors they believe are most important and thus narrow the programs their target consumers are likely to watch.

The index is being unveiled at this week's significantly toned-down upfront sales presentations.

Says head of sales Mike Shaw: "Every year we have to sing for our supper. Again and again, we have to prove our value, explain why our advertising viewing environment is powerful ... How do you prove that a TV ad unit works harder on ABC than on other places?"

Broadcasters are constantly searching for new ways to dissuade marketers from diverting their ad budgets online, where measurement is ostensibly easier via click-through counts or logging time spent watching a particular video clip.

Data sourced from Wall Street Journal Online; additional content by WARC staff