VIEQUES, PR: Digital auto advertising could be hit by an inventory shortage over the next eight months as presidential candidates take their campaigns beyond traditional TV buys, industry figures have suggested.

"Television, for the political arena, is already sold out, and has been sold out for months now," Mari Kim Novak, CMO of adtech firm Rubicon Project, told Beet.tv. "But there's billions of dollars that need to be bought for all the political campaigns."

A lot of that money will go into digital, with a possible knock on-effect on other advertising categories.

Tom Herman, CEO at programmatic platform DashBid, noted that there would be moves to reach a younger demographic that is increasingly choosing to view in OTT rather than linear television.

"With all the cord cutting that's really happening, and especially among the youth group, there's a real need to access that inventory," he said. "There's a lot of premium video inventory available in the OTT ecosystem that just hasn't been either addressable or it hasn't been measurable – the elections are going to drive a real hunger for that inventory."

A huge influx of political spending could well have an effect on other industries, noted Sean Buckley, SVP/Platforms at SpotX. "It could be a domino effect, which is really exciting," he said.

"Other folks are going to feel that [inventory] shortage as well… [for example], auto. It could have a residual effect, it's not just going to be limited to the political landscape."

Herman agreed, pointing out that the auto category was a heavy advertiser on OTT. "They've figured it out – they've been hungry for the inventory, and maybe they've been hungry for young buyers."

But OTT is not the only place to find younger voters. Howard Dean, who unsuccessfully sought the Democratic nomination in 2004, told the BBC that "Social media has replaced news media [in the US] as the principal source of information for everybody under 35 ... [Television] as a way of getting information to all Americans, just is not viable any more".

Yet political campaigns continue to put television at the heart of their media strategies. But "[h]aving a digital video strategy that supports cross-platform and cross-device viewing should be table stakes for every politician," according to Zohar Dayan, co-founder and CEO of Wibbitz, an automated video creation start-up.

He suggested in Ad Exchanger that mobile-first social platforms such as Instagram and Snapchat were effective mediums for political advertising and that parties should partner with a digital outlet to host an official debate.

Data sourced from Beet.tv, Ad Exchanger, BBC; additional content by Warc staff