Why GOW might not send a push notification to a player?
Game of Whales has a limit for the number of pushes: one push for a player within 1 hour.
So if the player has received the push notification from the special offer or another push campaign, he will not get any other push notifications (from other offers and push campaigns) during next 2 days. It will be good to divide the audience of special offers with push and push campaigns if you are going to launch them at the same time or if you are going to send several push campaigns within 2 days.
Personal push notifications, push notifications from personal special offers and push notifications about AI offers are sent without the limitations.