Funny enough, the web is being disrupted by smartphone apps and yet web devs are crying "fad" just like the hardware guys were yelling "fad" when the iPhone came out, but web apps on desktops aren't growing like mobile is (http://www.avc.com/a_vc/2012/07/mobile-is-where-the-growth-i...)... and so what happens to all the web app companies who are just hoping mobile doesn't kill their web apps or web sites?
In many industries it's as simple as making a product that does 80% or 20% of what the leading product does, but has a iPhone, iPad, Android app and you're likely to make sales on that fact alone. It's like going from desktop to web all over again.