For challenger brands like On Running, Under Armour, and Lululemon, a major celebrity signing can be a red flag for investors. It suggests a pivot from organic, hustle-driven growth to a more expensive strategy of paying to sustain momentum, which often precedes a stock decline.

For high-growth brands, the value of partnering with major figures like athletes isn't immediate sales. The real return is in access and the 'co-sign' effect. One partnership can unlock several other valuable opportunities, making the investment worthwhile through indirect, long-term benefits.

Reebok's resurgence stems from a unique partnership model. Instead of a simple endorsement, icons like Shaquille O'Neal are co-owners with strategic control, allowing them to authentically drive the brand's direction—a "let them cook" philosophy that contrasts with the over-management that led to its decline under Adidas.

Market size isn't the only driver for product expansion. On Running's entry into the relatively small tennis market was driven by their partnership with Roger Federer. The collaboration was seen as an infusion of an "athlete mindset" and "excellence" into the company's DNA, justifying the move beyond a purely financial calculus.

Building a brand from scratch requires prioritizing it above almost everything else—a commitment most celebrities can't or won't make. The endorsement model provides a safer, more suitable financial arrangement for the majority of entertainers who lack the time, understanding, or dedication for true ownership.

Instead of paying Roger Federer a traditional endorsement fee, On's founders proposed he become an investor and co-entrepreneur. This unconventional approach created a deeper, more authentic partnership and aligned long-term incentives for both the brand and the star athlete.

For a niche equipment brand, securing a top-tier athlete can be transformative. Rather than a small cash deal, offering a significant equity stake (e.g., 25%) turns the athlete into a co-owner, incentivizing them to actively build the brand among peers.

Top-tier creators are evolving their business models beyond simple sponsorships. They now leverage their influence to secure equity stakes or a percentage of sales they generate, enabling them to capture long-term upside and align more deeply with the brands they promote.

Baby2Baby transformed celebrity involvement from simple PR into a powerful negotiation tool. They offered celebrity endorsements to corporations like Huggies in exchange for multi-million dollar grants and massive product donations, creating a win-win-win flywheel for growth.