Over half of TV commercials fail to deliver any market-share growth for US brands in the long term.

That depressing insight for marketers came from an ad-testing program which has assessed more than 34,000 television spots – drawn from the automotive, beauty, financial, health, tech and charity sectors – in the United States and United Kingdom, and is based on a mix of consumer perceptions and media-spend figures.

Based on this dataset, research firm System1 has constructed a long-term effectiveness spectrum that runs from one-star TV commercials (expected to generate no meaningful growth over an extended period) to five-star spots (where growth of at least 3% is the forecast outcome).

“In the US, specifically, 54% of advertising falls in the one-star bucket, which is essentially delivering zero to very little market-share gain in the future,” Brent Snider, System1’s president/Americas and Asia Pacific, explained at the Breaking Brand event held by the Institute of Practitioners in Advertising (IPA), a UK trade body, in New York.