You might be the exception here but (a) Amazon.com is accessible from your mobile phone, do you not use that? And (b) “impulse buys from my phone” is indeed hard to quantify. How do we know that you’d make any impulse buys if the app was in front of you? Going to their website on a phone is as easy if not easier than using their app and the content is identical. Yet you don’t say that you make impulse buys that way. 80% of 0 is still 0.