There is no real evidence that computers can be programmed to intelligently invent and act on their own thought processes. All notable AI techniques to date specify in exhausting detail the thought processes that the AI should execute in carefully constructed algorithms. We're getting closer to the point where we can tell the computer to "think and act like a human" and in more and more domains it succeeds. But we're as far as ever from "think for yourself".
AdWords is and always has been the goose that lays the golden eggs, none of Google's other initiatives have ever rivaled that revenue. That's why they put so much effort into bolstering and optimizing their search results pages.