Stepped-wedge (cluster) rollout
All houses get the frog, but different akiya start specific features at randomized times.
Encouragement design (universal access, randomized nudge)
Everyone can steward; you randomize the “push”:
Rotating message frames: (a) social-norms prompt, (b) identity/“steward” framing, (c) neutral.
Visibility: live map pin size, confetti on check-in, leaderboard badge vs none.
Reminder timing: randomized notification schedule (e.g., morning vs evening).
Measure differences in uptake, visit chaining, and survey outcomes by nudge arm.