It’s triggering habituation by asking players directly for action & time investment, granting them immediate rewards for doing so, and offering more of the same for tomorrow.
“Developers crafted a lengthy checklist of tasks—train a character, equip special gear, battle other players—that dole out digital currency and other rewards when completed each day.”
“The latest mobile-game hit, “Super Mario Run,” rewards players for competing daily against friends.”
“A particularly effective tactic is team-based objectives, since players tend to nudge one another to participate”
“Exclusive offers, such as the opportunity to unlock a rare character during a one-week event, tap into people’s natural fear of missing out”