It isn’t. People who subtly mimicked their opponent were five times more likely to get what they wanted in negotiations than people who didn’t, according to one of the hundreds of research studies Berger drew on for his new book (which, tellingly, ends with 16 pages of densely-packed footnotes). Mimicry, which seems to be hard-wired in primates, has been proven effective in other contexts, too, like dating and job interviews. Ever wonder why some servers in restaurants repeat your order back to you word for word, instead of just saying something like “Okay” or “Got it”? You might assume it’s for accuracy’s sake, and maybe it is. Or maybe your server has noticed what research has found: Repeating customers’ orders precisely yields tips that average 70% bigger.

Berger’s point is that we all imitate each other, and react to being imitated, all the time whether we realize it or not (and we usually don’t). For marketers, this is a crucial insight. It explains why the more information consumers have about how many other people are buying something, the more likely they are to try it themselves — a notion Berger illustrates with examples from publishing (why a J.K. Rowling book, written under the pen name Robert Galbraith, flopped) to pop music (how did Britney Spears get so wildly popular, anyway?).

Some marketers are so convinced of mimicry’s power that they’re willing to pay to prevent it. Consider, for instance, the $900 Gucci handbag, covered in Gucci’s famous interlocking G pattern, that Nicole Polizzi got in the mail a few years ago. Better known as “Snooki” on the MTV reality show Jersey Shore, Polizzi hadn’t ordered the bag. It was sent for free — not by Gucci, but by one of Gucci’s competitors. Another cast member, Michael “The Situation” Sorrentino, got an even sweeter deal. Abercrombie & Fitch offered him “a substantial payment” to “wear an alternate brand” of clothing on the show, an Abercrombie press release said, in order to preserve its own brand’s “aspirational nature.”

Invisible Influence is that rare business book that’s both informative and enough fun to take to the beach. Some of Berger’s ideas might be controversial — see, for example, his analysis of why counterfeiting can actually benefit luxury brands — but they’re never boring. You might even put some of his suggestions to use at home. Getting kids to eat more vegetables, for instance, could be as simple as showing more enthusiasm for them yourself, even if you have to fake it. “If broccoli is the first thing on their parents’ plate, and the first thing their parents eat, kids will do the same,” he writes. “Even better if there’s a mock argument over which parent gets to eat the last piece.”