Much has changed in the past 25 years—between digitally recording our favorite shows to surfing the Internet to texting on smartphones—but TV is undeniably still America’s favorite pastime. More than 289.4 million Americans live in homes with TVs, and the average TV viewer consumes on average more than five hours per day. Whether they’re tuning into the news, a reality talent show or a football game, our understanding of TV viewing—including what is being watched and who is watching—is thanks to the National People Meter. An electronic metering system that transformed TV ratings through the delivery of overnight ratings, the National People Meter is celebrating the big two-five this year.