Smarter/more informative apps like Quora and Yelp are threatening Google search.
Mobile users use Google to search and discover more general things. They use apps as the primary source to get the quick, expert answer.
Even more, social networks like Facebook and Twitter are developing their own searchable archives. They will find a way to keep you within their environment to ensure you get what you’re looking for.
Google is still the best search tool. But what’s worrisome is that search accounts for 90% of the company’s yearly revenues. Advertisers may shift dollars to more specialized apps where people tend to look more.