“It is time for Adobe to announce the end-of-life date for Flash and to ask the browsers to set killbits on the same day.”

Those are the words of Alex Stamos, the Chief Security Officer of Facebook, and they follow the revelation of major Flash security vulnerabilities, one of which was exploited.

According to Stamos:

Even if 18 months from now, one set date is the only way to disentangle the dependencies and upgrade the whole ecosystem at once.

Of course, Stamos isn’t the first one to call for the death of Flash, and slowly but surely, the effort to eliminate Flash is gaining real momentum. The latest and perhaps biggest threats to Flash’s existence: anti-Flash updates to Chrome and now Firefox.

But don’t tell any of this to advertisers, who continue to use Flash, apparently to their own detriment.

That’s according to ad management firm Sizmek, which found that in Q1 of this year, over 5 billion rich media ad impressions were wasted because they consisted of Flash ads served to mobile devices without Flash support. Instead of seeing the intended rich media ads, static images were served up instead.

Why do so many advertisers rely on a technology that has lackluster mobile support? According to Sizmek’s director of research, Andy Kahl, “Creative designers and ad traffickers, who are responsible for determining ad formats, still stick to Flash that they have been using for a long time.”

A viable alternative, HTML5, might not be as familiar as Flash, but it isn’t exactly a new kid on the block, highlighting the inconvenient fact behind Flash’s staying power: for all of Flash’s flaws, actually getting everyone to abandon it is surprisingly difficult.

Unfortunately for advertisers, their industry’s love for Adobe’s once-ubiquitous application is harder and harder to come by elsewhere on the web. As Flash continues to lose supporters and gain detractors, nostalgic feelings around animated Flash ads will probably not save the technology from its eventual demise.