(CNN) Joe Biden made an aggressive early investment in digital advertising after announcing his 2020 presidential campaign, spending nearly $800,000 on Facebook and Google ads in less than a week in the race while dwarfing the rest of the field, according to data from both tech companies.

Biden's Facebook spending last week, at $406,860, was more than the combined total of the five 2020 Democrats who spent the most after Biden: Sen. Elizabeth Warren ($100,677), Sen. Bernie Sanders ($96,397), businessman Andrew Yang ($87,737), Gov. Jay Inslee ($56,142), and Mayor Pete Buttigieg ($55,992). Biden also spent ten times more on Facebook ads last week than the Trump 2020 re-election campaign ($39,481).

Biden was also by far the top political advertiser on Google last week. His 2020 presidential campaign has spent $388,900 on the platform overall, per the company's data, and at least $363,100 in the U.S. last week. The next closest 2020 Democrat in spending on the platform last week was Buttigieg, who spent $49,900, while Harris and Warren each spent just over $34,000 in the period.

The former VP spent a total of $406,860 on 1,336 targeted spots on Facebook, mostly announcing his entry to the race and aimed at either list-building or fundraising. In some of the ads, Biden is on camera asking for campaign contributions; others feature simple graphics, urging contributions by certain deadlines, or asking viewers to sign up for updates from the campaign. On Google, Biden's campaign has spent a total of $388,900 on 42 spots, mostly placing ActBlue donation links on search results pages.

Digital advertising is an increasingly critical expenditure category for modern campaigns, accounting for some of the biggest line items in candidates' first quarter FEC reports. Sanders, for instance, spent nearly $1.6 million on digital ads, or nearly a third of his operating expenses, in the first three months of the year. And digital ads accounted for more than half of former Texas congressman Beto O'Rourke's $2.4 million in operating costs.

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