How Google passed Apple to become the world's most valuable company

Alphabet passed Apple to become the world's most valuable company. Google's revenues overwhelmingly come from one thing: advertising. Ads account for about 90 percent of Google's overall revenues, and of this ad revenue three-quarters comes from ads on Google's own websites — including a large share for Google's market-leading search engine. The remaining quarter comes from Google's ad networks, which sell ads that appear on other people's websites.

While Google makes most of its money from ads, Apple makes most of its money from selling iPhones. The iPhone is a lot more lucrative than any of Apple's other products. Apple sold 231 million iPhones in 2015, generating $154 billion in revenue. In its most recent quarter, Apple generated twice as much revenue from the iPhone as all of its other products — iPads, Macs, Apple Watches, and so forth — put together.