This is like the idea that most of us like cakes. When we open a refrigerator door multiple times and see the same cake, we will not be as motivated to eat like if we opened the refrigerator door multiple times, and each time see a different cake (i.e., be exposed to a variable reward)….The objective of introducing better “reward management” abilities was to ensure users spend more time on Facebook as the rewards they are exposed to after the new abilities were implemented are presumed to be larger than bef

Source: Facebook News Feed: Design and “dark UX” are turning us into sleep-deprived internet addicts — Quartz