So, why not build mobile SAAS apps and charge for them? It seems like companies like Evernote, Remember The Milk, etc. that charge a premium for mobile as a val

So, why not build mobile SAAS apps and charge for them? It seems like companies like Evernote, Remember The Milk, etc. that charge a premium for mobile as a value add are making money there. My guess is the next big wave of mobile-first startups will be charging monthly subscriptions through IAP to small, but loyal users. Like 37Signals, but mobile.