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Please Don’t Make Me Download Another App | Our phones are being overrun
(www.theatlantic.com)
This is a most excellent place for technology news and articles.
The number I remember seeing was that on average, app users are seven times more profitable than web users. Sorry, no citation.
I suspect there's some selection bias in that regular/loyal users of a particular product or service are more likely to install the app, but it also affords the company greater access to send notifications and collect data. On the rare occasion that I install some random company's app for a specific benefit, I remove it when I'm done.