It’s certainly a function of a few variables on the talent side e.g. “size” of the talent, intensity of their involvement, how interested the talent is in the product or problem that you are solving, etc.
It’s also a function of a few variables on the company side e.g. pre or post product market fit, quality of management team, investors, secular tailwinds, etc.
There are also some category specific variables e.g “opportunity cost” of an endorsement opp in the category, category saturation with other celebrity brands, etc.