Men are more responsive to online ads than women, according to an eye-tracking study by picture provider Shutterstock.

Shutterstock’s study, carried out by eye-tracking specialists Lumen, found that simple image-led online ads that mirror the demographic profile of their target audience perform best.

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Men looked at the ads for 0.4 seconds longer than females (0.9 seconds vs 0.5 seconds) while noticing a third of the ads in the study, compared to a quarter for women.

Meanwhile image-led ads featuring children were shown to be more engaging to parents: those with children viewed 25 percent of these ads for an average of 1.3 seconds, compared to those without children who viewed 22 percent of the ads for an average of 0.8 seconds. Similar figures were found for images of an elderly couple being viewed more by people over the age of 55.

Data also showed that marketers selecting the correct images can double the amount of time that online ads are viewed on desktop.

The top-performing ad was viewed for 1.4 seconds, compared to a benchmark dwell time of 0.7 seconds.

“It’s notoriously hard to prove the effectiveness of online ads but this study goes a long way to showcasing what type of images engage viewers and therefore what kinds of ads are most effective. For marketers looking to produce online ad campaigns, they should seek to use simple imagery that appeals to the target demographic,” said Jeff Weiser, chief marketing officer at Shutterstock.

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The study was conducted in two phases. In the first phase, 150 panelists were shown 65 images (taken from Shutterstock’s picture library) in a randomized order to find out which were the most engaging. In the second phase, the top, middle and bottom performing images from the first study were used to create 16 image-led ads, which were then shown to a panel of 148 individuals, within a “typical online browsing environment”. Throughout the entire study, panelists’ eye movements were tracked to measure engagement.

This story originally appeared on Campaign.