San Francisco, California - YouTube sensation MrBeast posted a full video on Elon Musk's X for the first time this week, giving the struggling social media platform a boost.

MrBeast, real name Jimmy Donaldson, is the world's most popular YouTuber, with more than 230 million subscribers.

"I'm curious how much ad revenue a video on X would make so I'm reuploading this to test it. Will share ad rev next week," MrBeast posted Monday on the platform formally known as Twitter.

The video, which sees MrBeast and friends test out flashy sports cars, saw nearly 50 million views in just 14 hours after being posted.

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Last month, after being encouraged by X-owner Musk to post on his platform, MrBeast complained that even a billion views on X "wouldn't fund a fraction" of his costs of production.

"I'm down though to test stuff once monetization is really cranking!" MrBeast added in the post on X.

The upload by MrBeast was hailed by Twitter CEO Linda Yaccarino, who pointed to content deals signed last week with several viral personalities.

"Building a whole video ecosystem in plain sight... Who's next?" Yaccarino posted.

X last week announced shows from former CNN anchor Don Lemon, former Congresswoman Tulsi Gabbard, and sports radio host Jim Rome. Last year, X broadcast shows by conservative figure Tucker Carlson after he was fired from Fox, but Carlson has since said he will launch his own streaming service this year.

Musk's ambition is to turn X into an "everything app" that would combine social media with streaming and online shopping.

However, the chaotic management and controversial posts since his takeover of Twitter in 2022 has seen user traffic drop and major advertisers halt spending on the platform. Last year, Musk bitterly criticized advertisers who had left the platform, saying they would kill X.

This advertiser exodus gained momentum after Musk endorsed an antisemitic conspiracy theory on the platform.