Google's new smart products might force it to rethink its ad business

Google Inc.'s latest technological marvels point to a future where you'll never need to visit websites, write a term paper or stress over what to buy for your mother's birthday. For consumers seeking convenience and speed, it all sounds great. But how will any of it make Google money? The Mountain View, Calif., company's apparent transition from go-to search engine to omnipresent virtual assistant probably will require rethinking its advertising business. By tracking Web browsing, emails, chats and more, Google has become a dominant force in digital ads.