Flash is bordering on obsolete at this point thanks to the rise of mobile and HTML5, yet advertisers are still running a ridiculous amount of Flash ads despite the fact that they default to static displays on mobile devices, which likely means fewer clicks.

Sizmek has released a new study, which illustrates just how common this is and notes that it’s a “major issue”.

“This raises questions as to whether or not marketers are aware of how many of their ads are not being seen properly and how much ad spend they are wasting,” a spokesperson for the firm tells WebProNews.

“As mobile inventory grows, the channel is also changing, particularly in the realm of rich media. The days of Flash-supported inventory on mobile devices are numbered,” the report says. “iOS devices have never had native Flash support, and it’s been six full operating system versions since Android devices supported Flash. This means that only 11% of Android devices are capable of supporting Flash, and those devices are running significantly out-of-date software. Because mobile support for Flash inventory is nearly extinct, rich media ad formats that rely on Flash are likely to default – or revert to a single, static image – nearly 100% of the time. This means 5.35 billion rich media impressions served to mobile devices were squandered in Q1 of 2015 alone.”

According to Sizmek’s findings, only 8.3% of HTML5 impressions defaulted, while these formats represent less than half of rich media ads served to mobile devices.

“The Flash mobile default problem isn’t exclusive to just a few advertisers,” the report notes. “Among campaigns that served at least 1 million impressions in Q1, the average default rate was 35.2%. Many advertisers had it much worse than that – 36% of the advertisers in this sample defaulted much more than average, including the 12% of advertisers that never successfully served a rich media ad to a mobile device. The rate of rich media failure was much lower on desktop inventory, where 60% of advertisers defaulted at a rate of less than 3%.”

As the report points out, a lot of advertisers may see the defaults as not a big deal since viewers are still seeing the ad in some form via a static image, but it also points to data showing that HTML5 ads get much better click and interaction rates.

You can take a look at the full report here.

Images via Sizmek