Photo

Political advertisers hoping to attach their ads to YouTube replays of Taylor Swift’s Grammy speech may be out of luck in Nevada and South Carolina: There’s essentially no reserve inventory left on the popular platform ahead of the coming primary elections and caucuses there.

As political campaigns and their “super PACs” have flooded broadcast and cable stations since January, they’ve also been pumping ad after ad onto YouTube in the early states. In New Hampshire and Iowa, YouTube’s reserve inventory completely sold out well before voters cast their ballots or headed to a caucus.

Certain segments, such as those directed at younger age groups or households with children, were sold out much earlier in the year. But as the desire for advertising increases closer to decision day, other, broader segments of the market have been snapped up as well.

Unlike on broadcast television, campaigns are not given special dispensation on YouTube. There is no federal regulation guaranteeing a campaign would be given time on the platform if other candidates advertise on it. YouTube is only able to make available what it has, and that’s it.

YouTube, and digital advertising in general, has been particularly attractive to super PACs and outside groups this cycle. While those groups find themselves paying sometimes nine or 10 times the rate a campaign would on broadcast television in a crowded market, there is no such difference for online advertising. A super PAC would pay the same rate as a campaign online.

While the reserved inventory is gone, campaigns hoping to increase their ad purchases can still get in through a real-time auction process. But that process is far from guaranteed and often more expensive.