When Academy-Award winning actress Gwyneth Paltrow founded her lifestyle brand in 2008, all she had was an earnest newsletter and a name: Goop (two “o”s between her initials). Her friend Peter Arnell, a New York branding expert, had told her that all billion-dollar internet company names have two “o”s in them (think Google, Yahoo ), recalled Ms. Paltrow, 45. “I thought it was stupid and funny.”

A decade later, Goop is no joke. It is arguably the most prominent celebrity-run lifestyle brand, encompassing: a website; virtual as well as brick-and-mortar retail shops; a line of clothing; Goop by Juice Beauty products (including $140 replenishing night cream); bicoastal summits with $2,000 tickets, plenty of turmeric and tarot card readings; a printed magazine; and vitamin packets with names like “Why Am I So Effing Tired?”