Excerpt from this article:
Basically, we’re on our smartphones a lot more when looking things up than we are on our desktops. And we’re fragmented in the way we search now as well. Google is all search for everything but can’t necessarily tell us in a click the best restaurant or what the price is on a coveted item. We use niche travel apps such as Kayak to look up travel info, Trulia to search for homes and local business search company Yelp to look up local businesses.