Agreed apart from:

> One advantage of a mobile app over a mobile web site is that you can use the accelerometer

Accelerometer API access has been available on mobile web for ~ a decade. I think it'd actually be more trouble than it's worth to listen for a "tilt" to shift the view and misdirect the user's tap. Most UI's just put the ad dangerously close to an element that's also interactive, or style the ad to look nearly identical to the other content in the feed, like reddit. It's to make you encounter ads and maybe tap on them purposefully or accidentally. They will happily take either.