Based on what? Celebs & pop stars are already getting paid millions per year to speak/play at private events. Commoditizing that market and making it accessible on a variety of platforms at a variety of pricing tiers is going to bring in a ton of money.
How much is a 'ton'? 5 Million? 10 million? 100 million?
How big really is the market for a celeb sending a custom 10 second video talking about something, and can this entity really control that market? How do they maintain their margins.
Take Social Media for example, it'd seem there doesn't seem to be a massive player that controls how the sponsorship money flows into influencers, and not for a lack of trying.