Consumers used to skipping pre-roll ads on YouTube videos have encountered a new enemy: mandatory watching. Designed as a counterpunch to AdBlock and other avoidance strategies, forced impressions have not been so popular.

Geico’s award-wining mini-ads took a much more successful approach. By deliberately creating absurd ads so short they could not be skipped, viewers were sure to keep the company in mind. Advertisers continue grappling with the challenge of grabbing an audience prepared to skip as soon as possible to the content they hope to see.

Google’s Unskippable Labs has tested the power of mobile video ads ranging from the short (15 seconds) to long-form videos lasting several minutes. The short ones definitely don’t always win. On the second day of &THEN 2016, Ben Jones of Google will discuss the findings of campaigns by L’Oreal and Mondelez, among others, and how platform and length impact a brand’s goals.

Shorter, Not Necessarily Sweeter

Attention spans are actually not getting shorter, at least as far as ads are concerned. Looking at the most-watched YouTube ads (by choice) in 2015, the average length was over one minute, with two of the top three longer than three minutes.

Google’s Unskippable Labs study with Mondelez focused on the viewing habits of a short video (15 seconds), a slightly longer one (30 seconds) and a long-form spot exceeding two minutes. Each focused on the daily activities of a Hispanic family. The shortest was the one most frequently skipped by viewers, while the 30-second ad had the highest view-through rate.

While a small number of viewers saw the longest (2:17) video to its completion, the key feedback surrounded the limited branding within the ad. Only after one minute did the Mondelez brand logo appear on the screen. Of the three, the shortest video had the highest recall rate but did little to connect the viewer to the brand.

Professional Ads vs. Low Budget Ads

Another Google study pitted a professionally styled and filmed L’Oreal Paris makeup ad against a low-budget tutorial and a spot by a beauty blogger to see which appealed to women more as pre-roll ads worth watching through. Contrary to DIY trends, the pro ad did the best among women of all ages, though the low-budget tutorial was more memorable to the youngest groups.

Along with better view-through rates, the traditional ad had much higher favorability scores than the other ads in the study. Meanwhile, the low-budget tutorial by a “normal” young woman had the highest click-through rate of the bunch. The platforms, whether mobile or desktop, had little impact on the results.

Google’s Ben Jones remarked on the success of both ads. “The TV commercial was aimed at an older audience, and the older audience responded incredibly well,” he said. At the same time, Jones said the parallel success of the low-budget spot suggested to L’Oreal multiple ads on the same topic were worth the money.

Finding the right formula for mobile video is tricky as YouTube gets more flooded with content. Join Ben Jones on the second day of &THEN for “The Unskippable Future of Video” and a look at how a spot can affect your branding goals.

This article is brought to you by &THEN, DMA’s annual event. Click here to join the leaders of the marketing community and explore the science of creativity in Los Angeles, October 16-18. Save over $500 when you register online.