>As per previous posts there are numerous vendors who earned their billions from served web interfaces (e.g. ebay, priceline, godaddy, amazon) who nevertheless promote locally installed apps for mobile devices. Why? Perhaps it's temporary pending 100% reliable mobile networks- though the niche experts assert that there never can be such a thing.

Does an installed app put an icon on your device? If so, that's eyeball share you don't get with a generic browser. Also starting an app has to be faster than starting the same functionality delivered via a browser. Eliminate any impedance between users and your goods and services.