When Yelp was first launched in 2004, it flopped. The company’s initial model of an email-based referral service failed to take off until its creators realized users were taking the platform into their own hands; in lieu of sending one another recommendations via email chain, they began using a “hidden” link at the bottom of the startup’s website to write unsolicited reviews of everything from doctors to restaurants. Yelp 2.0 launched in 2005, and gave those reviews a more visible place to live online — one that emboldened users to feel more authentic stewardship, by way of direct authorship, over hyping up the businesses they enjoyed (or didn’t). The startup bought a whopping 20-million-business database , and amplified a world of reviews outside of the restaurant- critic echo chamber. It was a fresh democratization of information, which was itself one of the more optimistic legacies of the Y2K internet.

It’s been over 20 years since Yelp was founded.…