The Economist/YouGov poll was a so-called opt-in poll, in which pollsters often pay people they’ve recruited online to take surveys. To create a pool of people to take opt-in surveys, polling companies recruit through ads that pop up on social media, internet search engines, and even during video games, offering cash or rewards to complete surveys, said Kennedy. In some sense, he suggested, most polling is now nonprobability polling: When only 2 out of 100 people respond to a survey, it’s much harder to claim that those views are representative, said Rivers.