While Facebook and Amazon are formidable competitors, Google is the top destination for marketers looking to reach consumers online. It accounted for 31 percent of digital advertising around the world last year, according to the research firm eMarketer.

Google said advertising revenue from “Google properties” like search and YouTube was $27.02 billion in the fourth quarter, up 22 percent from a year earlier.

The company’s ad business is shifting as more consumers use mobile devices for access to the internet. Alphabet reported a 66 percent increase in clicks on its ads, although the revenue per click fell 29 percent during the quarter. In other words, people are looking at Google’s ads more often, though the price of those ads is dropping.

Mobile ads cost less than ads viewed on desktop devices. But the company has offset that decline because search ads take up more screen space on mobile phones — making it more likely users will click on them.

Alphabet’s quarterly results beat Wall Street’s estimates, but the company’s share price was down about 2.6 percent in after-hours trading on Monday.