Facebook’s video ad strategy is not as developed, he said, but he uses Facebook to build his brand. Mr. Paul, who is exceedingly diplomatic about the different platforms, said he keeps dialogue to a minimum on Facebook because it serves a global audience who may not all speak English. He focuses on physical stunts — such as performing splits in locations around the world.

Last year, Facebook paid as much as $220,000 for top YouTube stars, including Mr. Paul, to produce exclusive content for Facebook Live. However, the deals did little to entice YouTube stars to post more frequently on Facebook. Facebook said those deals were to support stars as they experimented with Live, not an attempt to recruit talent to its platform.

“As long as YouTube continues to be a place where creators can amass a large audience, it’s always going to be a draw until another platform can match its revenue dollars,” said Joshua Cohen, co-founder of Tubefilter, a site devoted to the online video industry.

Facebook started testing the new advertising program earlier this year to allow some creators, like Ms. Clery, to place 15-second ads in videos. Creators in the program said advertising revenue from Facebook was comparable to YouTube, although many cautioned it was still early. Facebook said it was “pleased” with the program and planned to include more creators.

Also, both companies are pushing to help creators land so-called influencer marketing deals — connecting social media stars with companies that want their brands or products promoted. Last year, YouTube acquired FameBit — a marketplace to help marketers find influential stars — while Facebook made more people eligible to promote posts from brands.

Facebook and YouTube are also adding features that make them more alike. Last week, YouTube introduced a mobile feature to directly share videos with friends and maintain group messaging threads. YouTube also started a pilot program to allow major stars to post nonvideo content to their pages — creating a Facebook profile of sorts with photos and text.

Last year, Facebook added a dedicated video tab — a mini-YouTube within its mobile app — so people interested only in watching videos on Facebook have a place to go. And there are reports that Facebook is bringing exclusive content from media companies to the video tab.