Every app i've seen use this uses it to implement a "microsite". for eg nytimes made an instant app for the crossword puzzle on android... except if i'm into

Every app i've seen use this uses it to implement a "microsite". for eg nytimes made an instant app for the crossword puzzle on android... except if i'm into crossword puzzles i'll download the app anyways,why the hell would i download the instant app everytime unless it was part of my "flow" ie read the new york times paper and then the crossword is sent to my phone automatically or something? except i'd be reading the paper on my phone as well? the usecase for these kinds of things is so muddled and unclear i don't understand the point...