Dive Brief:

• Dwayne Johnson's partnership with Under Armour was the highest-ranking celebrity endorsement deal among fashion and retail marketers based on perception analysis, audience match and risk assessment, according to a new report by the researcher Spotted. 
• Rounding out the top 10 highest-scoring celebrity-endorsement campaigns were Tommy Hilfiger and Winnie Harlow, Crate & Barrel and Reese Witherspoon, Rag & Bone and Ashley Graham, Crocs and Drew Barrymore, Amazon and Anthony Hopkins, Hugo Boss and Chris Hemsworth, Reebok and Gal Gadot, Rolex and Roger Federer and Lord & Taylor and Christie Brinkley. 
• The lowest-scoring campaigns, in order, were Adidas and Mura Masa, Burberry and Iris Law, Reebok and Lil Yachty, Tiffany & Co. and ASAP Ferg, Gap and Awkwafina, Gap and Metro Boomin, 7 for All Mankind and Cleo Wade, Saint Laurent and Kaia Gerber, Tommy Hilfiger and Christian Combs and Diesel and Shayne Oliver. 

Dive Insight:

While high-profile endorsements are an age-old marketing tactic, the Spotted analysis highlights the characteristics that can help make for successful partnerships, including celebrity recognition, authenticity, trustworthiness and brand match. Johnson, who's sometimes known as "The Rock," helping bolster Under Armour's perceptions is perhaps unsurprising: the actor is one of Hollywood's most bankable stars and has built a large social media presence. His latest major campaign with Under Armour, "Will Finds a Way," is also reportedly the brand's largest-ever campaign in terms of investment and global reach.

However, while Spotted's findings underpin the bones of what makes for a good celebrity ambassadorship, the actual value of these types of partnerships has come under growing scrutiny in recent years, especially when it comes to their effectiveness in engaging key young consumer segments. A 2017 Roth Capital Partners study found that 78% of millennials either don't like celebrity endorsements or were indifferent to them. Asked if they would be more likely to make a purchase based on a celebrity endorsement, 27% of millennials disagreed, 19.5% somewhat disagreed and 31.8% were indifferent. 

Under Armour and Johnson's deal is a bit of case-in-point in that regard. Despite the strength of its partnership, Under Armour has struggled to retain a strong brand identity in recent years and has faced declining sales in a highly competitive athletic apparel market. Those challenges have been felt in executive churn as well. The company last week confirmed that Adrienne Lofton, who helped spearhead "Will Finds a Way," would be leaving the company. An announcement of her departure comes just months after Global CMO Andrew Donkin. Donkin spent just 15 months in the role. 

In 2017, brands spent an estimated $35 billion on celebrity endorsements, according to MarketWatch data cited in a CNBC write-up. Celebrity endorsements can be risky for brands, especially if the spokesperson is involved in a scandal or other unsavory incident. CNBC noted how in 2009, several brands, including Gillette, Gatorade, AT&T and Accenture, cut ties with Tiger Woods after he was involved in a car crash and several alleged extramarital affairs.