A few months ago, Amazon's competitor Flipkart started asking users to order via the app rather than through the browser. That's when a lot of my friends and I switched to Amazon. I never really understood the reason for insisting on ordering via the app.
Apps don't have a good way to convey that they are using HTTPS, so I don't like the idea of entering my credit card details in an app. Most internet banking gateways in India aren't yet mobile optimized, so that's inconvenient too. (Internet banking is a popular alternative to debit cards in India; merchants re-direct users to their bank's website where users can login and agree to paying the merchant. It's actually a lot more convenient than credit cards because you only have to remember your bank account's username and password.)
Apps don't have a good way to convey that they are using HTTPS, so I don't like the idea of entering my credit card details in an app. Most internet banking gateways in India aren't yet mobile optimized, so that's inconvenient too. (Internet banking is a popular alternative to debit cards in India; merchants re-direct users to their bank's website where users can login and agree to paying the merchant. It's actually a lot more convenient than credit cards because you only have to remember your bank account's username and password.)