“Half the money I spend on advertising is wasted; the trouble is I don't know which half.” That memorable statement is credited to U.S. department store pioneer John Wanamaker, and more than a century later and despite marketers’ use of high-quality data to fuel successful marketing initiatives, the sentiment is still relevant today. Data from a study published by marketing measurement and optimization firm Marketing Evolution shows that 21 cents of every media dollar spent by organizations in the past year was wasted.

While marketers rely on high-quality data, Marketing Evolution’s study, “Why Marketers Can’t Ignore Data Quality,” shows that they struggle to achieve it. The study also shows that while 82 percent of organizations place a high priority on refining data quality, 26 percent of marketing campaigns were hurt by substandard data in the past 12 months.

The report identifies seven dimensions that best define data quality: timeliness, completeness, consistency, relevance, transparency, accuracy and representativeness. Per study findings, wasted media spend is the highest ranked repercussion of poor data quality (37 percent). The 21 cents of waste the study identified was due to poor data quality, resulting in inaccurate targeting (35 percent) and lost customers (30 percent).

The majority of respondents (87 percent) ranked “high-quality data” as important or very important to marketing success, and as much as 32 percent of marketing teams’ time is spent managing data quality, and 26 percent of campaigns in the last year were hurt by poor data quality, on average.

“Data offers today’s marketers an extraordinary advantage and is key for improving customer understanding and engagement,” says Rex Briggs, CEO of Marketing Evolution. “But data is only as valuable as the insights it produces, the actions it influences and the results it fosters. Without the ability to ensure data integrity, marketers are relinquishing their most powerful tool—and a massive competitive advantage.”