Believe it or not, banner ads remain the most effective ad format.

AppNexus took a snapshot of the marketing world based on vendors' users' views, providing insight into what is working, and what is not, in the actual day-to-day execution of campaigns. The AppNexus survey Q2 2015 Digital Advertising Index, which is based on more than 80,000 campaigns transacted on its platform that quarter, revealed banner ads still offer marketers the highest click-through rates.

This may surprise some marketers who don't typically place a high value on the sometimes overlooked banner ad. However, banner ads offered marketers the least expensive format on the AppNexus platform at $0.16, and also the second highest clickthrough rate at 0.04%, barely trailing expandable ads at 0.05%. For clickthrough those two ad formats significantly outpaced interstitial, pop-up and skins, and skins was the most expensive format exceeding expandable ads by more than a dollar.

Other key findings included the dominance of desktop ads over mobile with 64% of campaigns targeting desktop users, compared to 47% targeting the mobile web and 32% targeting mobile apps. Overall ad spending was split between the U.S. (52%) and the rest of the world, with the U.K. at 14%, France at 6% and Canada at 5%.

"There’s a lot of buzz about the banner ad being dead, and about consumers, marketers, and publishers alike shifting their attention to mobile. But the Q2 index shows that in fact the banner ad has high CTRs and competitive prices, particularly compared to interstitials, pop-ups, and skins," Pat McCarthy, SVP of Marketing at AppNexus, said in an interview with Marketing Dive. "Marketers have the opportunity to allocate budgets across both desktop and mobile, capitalizing on data around impression availability by time-of-day and day-of-week. When segmenting budgets, marketers should consider device and time, and leverage data in order to do both well."

In marketing, transparency matters

In April, AppNexus introduced AppNexus IQ, a set of policies and products that enable more comprehensive enforcement of its inventory quality standards. McCarthy said development benefited all participants in the digital ad space by offering a level of oversight.

“The introduction of AppNexus IQ proves that committing to quality and transparency results in benefits for buyers and sellers in the form of increased revenue for publishers, increased post-click conversion rates, and a rise in RPMs from strongly performing tags,” McCarthy said. “AppNexus' mission is to create a better Internet, and our commitment to quality is a critical part of that mission. Marketers will benefit significantly when they’re part of an ecosystem that values trust and transparency.”

McCarthy added that insights into spending and effectiveness should give marketers some ideas on improving messaging. The report found telecommunications, alcoholic beverages, financial, automotive, and home and décor combined to make up 61.4% of spending with telecomm leading the way by far at 29%. But the most effective ads were about jobs and family and the most valuable ads were about sexual health and saving money.

McCarthy put these insights into perspective, “In spite of telecommunications and alcoholic beverages leading the way in spend, the most effective ads were about jobs and family – an insight which should help shape marketers as they craft their messaging.”

One final insight from the report was how marketers’ reliance on desktop advertising, making up 64% of the campaigns on the platform in Q2, impacted impressions. The highest rate of impressions happened between 10 and 11 p.m. ET, a time that most people are at home and awake. In terms of day of the week, impressions were lowest on the weekend when people were likely to be out of the house and away from their desktop computers.

"Quality and transparency are the future of internet advertising," McCarthy offered, adding that by aligning themselves with trustworthy platforms, "not only will [marketers] realize better performance and value, but they will be part of making the internet better for consumers today, and in the months and years to come."