There is a significant drop off early on which could mean a number of things such as; players didn’t like the context/theme/artwork of the game, perhaps the icon/description/screenshots were misleading or perhaps players just didn’t know how to get to the next section. If you’re walking players step by step through the tutorial (also known as gating) then the last scenario is unlikely. There’s another drop towards the end. It could be related to a technical issue, a login screen (e. g. Facebook) or player confusion with the UI or information presented.

It’s instilling the perception that you’re being generous to players. Generosity creates a positive emotion with players, and you want those types of emotions or feelings associated with your game. It shows players the IAP screen. We all want our players to spend premium currency, but we want them to buy it even more. Explaining how to do something with players can work for a small percentage, but showing players how to do something is much more effective.  

You want to be able to remind those players that they haven’t fully experienced your game. Just remember not to be pushy or obnoxious with your alerts. There’s probably no reason to call them back more than once per day.