The　increasing　unethical　behaviors　in　the　application　market　make　platform　governance　increasingly　important.　To　our　knowledge,　in　this　article,　the　effectiveness　of　punishments　for　unethical　behaviors　and　the　responses　of　app　developers　and　users　to　the　implementation　of　punishments　have　remained　unclear.　So,　the　purpose　of　this　article　is　to　examine　the　spillover　effect　and　the　mechanism　of　platform　governance　of　Apple　app　store.　Based　on　the　weekly　observation　of　2500　apps,　we　examine　the　spillover　effect　of　punishments　of　different　severity　on　previously　unpunished　developers＇　adaptive　reaction　(e.g.,　weekly　updates　and　weekly　new　release)　and　users＇　evaluation.　We　verify　that　punishment　has　effects　on　the　developer＇s　adaptive　behaviors　in　the　long　term　but　does　not　have　effects　in　the　short　term.　However,　severe　punishments　cause　developers　to　conduct　adaptive　behaviors　that　are　not　conducive　to　the　app　store.　Furthermore,　we　accentuate　that　the　effect　of　different　punishments　on　user　evaluation　depends　on　the　type　of　apps　(i.e.,　utilitarian　versus　hedonic).　We　also　discuss　the　implications　of　our　results　as　they　directly　relate　to　the　governance　of　the　app　platform　and　the　benefits　of　users　and　developers.　More　broadly,　the　findings　contribute　to　building　a　healthy　app　store　ecosystem　composed　of　platforms,　developers,　and　users.