As the web moves to a more visual landscape, it’s not surprising that advertisers are becoming more attracted to in-image advertising, and publishers are recognizing the untapped source of revenue their editorial images now hold.

As it recently did with native advertising, the IAB has issued a primer on in-image advertising to help establish common terminology, best practices and offer examples of how advertisers and publishers are successfully employing this relatively new form of digital advertising.

In-image advertising is essentially a subset of native advertising, and sometimes also referred to as image-based advertising. In-image ads can take many forms, but they appear within an editorial image on a web page. They can be display ads that show product information overlaid on editorial images or they can be video or rich media ad units that only appear when the user engages by hovering or clicking on the ad.

Venture capital is now flowing in to the sector, with in-image platforms and service providers such as Luminate, Cortica and Image Space Media receiving nearly $100 million in funding collectively, according to the IAB.

Each of the case studies highlighted in the primer underscore the eye-popping engagement metrics early adopter advertisers are generating from in-image campaigns. Here’s a look at two of the five campaigns profiled.

Cat’s Pride ran an in-image ad campaign through GumGum’s platform using rich media banner ads that expanded to show a video overlay when users engaged with the ad. The ads rean on several newspaper websites, including NYDailyNews.com shown below.

According to GumGum’s stats, the campaign yielded a 1.18 percent click-through rate on the ad and a 4.22 percent click-through rate from the video overlay to the Cat’s Pride website.

Anyone who’s run standard display campaigns lately will understand the significance of a CTR above 1 percent, heck above .5 percent — it’s a bit of a throwback to the early days of display advertising. Whether these types of engagement rates will hold as in-image matures, or if they’ll decline as they did with traditional banner ads is a viable question. For now, though, it’s fertile ground.

In another example, Activision partnered with Stipple to promote and drive pre-orders for its new game, Call of Duty: Ghosts. The ads included videos, photos and storefront links that appeared on hero images on gaming and social media websites. The ad content displayed when users touched the “content atoms”, or icons on the image. The engagement rates on the ads was 225 percent and the click-through rate was 54 percent. The average time spent with the ads was greater than three minutes.

The benefits of in-image advertising include the fact that they are usually contextually-relevant and appear in-line with visual content, and they are viewable to users.

The branding-driven in-image ad campaigns that the IAB looked at generated an average 37 percent brand lift, which is almost three times the industry average, according to Nielsen Online Brand Effect norms.

As the IAB points out, capitalizing on even a small percentage of the editorial images online has the potential to represent a sizable portion of the $7.5 billion display advertising market in the coming years.