By Michael Luca

Few recent innovations have been as simultaneously celebrated and maligned as the like button. In "Like: The Button That Changed the World, " Martin Reeves and Bob Goodson trace this social-media feature from a forgotten sketch drawn at Yelp through its spread on platforms including Facebook and YouTube -- a story of collective drift and what the authors call "Exhibit A of how software innovation worked in Silicon Valley" at the turn of the 21st century. What begins as a common startup tale -- complete with office desks salvaged from the street -- quickly becomes a broader account of a product that has transformed the online landscape in ways both helpful and horrifying.

Mr. Reeves is the chairman of the BCG Henderson Institute, the think-tank arm of Boston Consulting Group; Mr. Goodson is a Silicon Valley founder. As the authors tell us, the genius of likes lies in their ability to harness online crowds, "gauging people's engagement levels and emotional responses" and "spurring more content creation." A like is simultaneously an outlet for users to express an opinion, an incentive for platforms to drive audience participation and a signal that influences what others consume. Likes don't simply reflect popularity -- they create it. As I've explored in my own research, crowdsourced signals shape consumer decisions, from what we watch to where we eat.

Designed well, this feedback loop can benefit both consumers and businesses. But its proliferation has also contributed to "mental health issues, privacy violations, and polarization." As the authors note, "the downside of how uplifting it feels to get likes is how dispiriting it feels not to get them." And in social-media feeds, "the content served up to you not only reflects your inclination to hold certain beliefs but also filters out information that might usefully challenge them."

Generating ever more data "to analyze people's sentiments and preferences," likes have also led to more invasive forms of surveillance and targeting.

The book treats the social effects of online crowds primarily as cultural byproducts -- but they can escalate into real consequences: anxiety, exclusion, even economic disadvantage.

In the end, the like button may be a simple piece of code -- but the social machinery it set in motion is anything but.

Mr. Luca is a professor of business administration and the director of the Technology and Society Initiative at Johns Hopkins University Carey Business School.

(END) Dow Jones Newswires

June 12, 2025 13:58 ET (17:58 GMT)

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