WASHINGTON DC: Politicians across the US are increasingly turning to online advertising to get their message across, including the use of gaming platforms and streaming radio to reach a younger demographic.

Online political spending has already grown at a four-figure rate over the past four years and will reach an estimated $270m during the current midterm election campaign. By 2016, that figure could top $1bn, overtaking newspapers, direct mail and telemarketing, according to figures from research firm Borrell Associates quoted in Politico.

President Obama was famously ahead of the curve on digital electioneering, recruiting technologists and digital analysts to his 2012 campaign and making effective use of social media and email marketing to encourage action and solicit donations.

Two years later, candidates for the midterm elections are following suit and Borrell Associates anticipates a "digital juggernaut" in forthcoming election cycles. Strategists from the two main parties indicate that up to 20% of campaign budgets could be allocated to digital in 2014.

"There's no exact figure," said Brandon Hall, partner at political media firm Kully Hall. "It's just assessing the market and looking at what can be done."

Television would continue to have the biggest impact on voters, he said, but "the digital piece has to be a part of it, it has to be a layered approach".

Amanda Bloom, a consultant at campaign specialist BASK Digital Media, was blunter, telling a recent conference: "If you're trying to hit males 18 to 34, you probably want to be all digital."

Examples of how this might be done came from Florida, where the incumbent governor has run ads on the Xbox gaming platform, and from Georgia, where one candidate ran ads on online radio station Pandora.

But, as Wesley Donehue of campaign consultancy Push Digital noted, the needs of individual campaigns are dictated by the target audience – ads on Pandora might work in Georgia, he said, but in Arkansas traditional radio ads were a better bet.

Whatever the local preferences, digital is now firmly established as a player in the political world, as evidenced by the TV commercials which regularly draw the attention of viewers to a campaign's Facebook, Instagram, Twitter and YouTube pages.

"If you were asking me what's the single biggest change in advertising content in the political ads we see in 2012 and now, that's it," said Elizabeth Wilner, head of political campaigner tracker Kantar Media CMAG.

Data sourced from Politico, Mashable; additional content by Warc staff