Interesting blog

"Meta may be one of the very few companies that can monetize a personal agent through advertising without ever showing an ad inside the agent itself. "

Meta acknowledges that Muse appears as your own activity when it browses, so a merchant site it visits for you might use that visit to show you an ad on Instagram.
meta

That lets Meta keep ads out of Muse while still collecting commercial intent signals for its feeds, a loop few rivals can copy without both merchant tracking tags and a vast owned ad surface.

Instead of in-agent ads, Zuckerberg has promised to fund Muse's free tier with a small transaction fee, reportedly paid by merchants rather than purchasers, whose size Meta still hasn't disclosed.