As Stafford explains, our love for the Internet is rooted in the fact that human beings, in Ghose’s words, “compulsively seek unpredictable payoffs.” The cognitive-reward structure offered by services like email and social media are similar to those of a casino slot machine: “Most of it is junk, but every so often, you hit the jackpot.” … As researchers found in a 2001 article in International Gambling Studies, systems that offer a low-cost chance of winning a very large prize are more likely to attract repetitive participation and, in turn, stimulate excessive (and potentially problematic) play.