I would have to disagree there, the beats by dre campaign was HUGELY supplemented by above the line advertising, as well as digital advertising and supplemented not only by any influencers but celebrities. I would encourage you to look at studies on influencer only campaigns vs ones that are augmented by other forms of advertising as well as the brand they pitching for.
Performance marketing is very different from branding
Can you hit me up with a link to such studies? I am interested :)