YouTube is making a play for valuable political dollars via a new tool that provides an automated way to reserve ad slots on the video platform. According to The Wall Street Journal, it has been such a boon that many buyers rushed to lock in time as far ahead as the end of February. The newspaper reports that the YouTube initiative aims to “take advantage of the growing sums being spent on advertising by a historically large field of presidential candidates”—while also looting the coffers of the likes of local TV and Facebook, which currently take a lion’s share of political ad spend.

“People acted quickly with what was available,” said a staffer for one of the Democratic front-runners in the WSJ, adding that the campaign wiped out available slots in early voting states such as Iowa and South Carolina.

YouTube’s new Instant Reserve tool borrows a tactic from traditional TV, where advertisers can book ads months in advance to lock in slots for the best programming at discounted rates. Before it launched Sept. 3, campaigns had to coordinate with salespeople to book ad slots, the Journal story explains.

YouTube is expected to take in about $11.38 billion in global ad revenue this year, according to eMarketer, a 20% increase from a year earlier. A Google spokeswoman said the company is testing the tool with political advertisers as well as hundreds of others, including media and consumer goods companies. Political ads are subject to additional scrutiny, from verifying the buyer’s identity to embedding a disclosure in the spot stating who paid for the ad, the spokeswoman told the Journal.

Political TV ad spending is expected to reach $4.78 billion in 2020, compared with $2.85 billion for online and digital political ads, according to Borrell Associates. And adding to the advantage of the new tool, YouTube allows more targeted advertising than traditional TV. “A YouTube ad can, for instance, be made to appear exclusively ahead of videos viewed by people identified as left-leaning voters in Polk County, IA, days before the Feb. 3 caucuses,” media buyers said in the story.

President Trump and the nearly 20 Democrats running for president have so far spent $21.8 million on Google and $43.5 million on Facebook, according to Acronym, a progressive nonprofit that tracks digital spending. As the actual voting gets nearer, campaigns tend to shift their advertising to video spots, which are seen as a better tool to persuade voters and get out the vote, those media buyers noted.

Looking ahead, on Nov. 15, Google plans to let ad buyers reserve slots on YouTube for the entirety of 2020, a presidential campaign digital buyer told WSJ. Users of YouTube’s new tool can reserve slots but won’t have to pay until the ads actually appear, media buyers said.