He applauded Facebook CEO Mark Zuckerberg for following what former Intel CEO Andy Grove used to preach in Silicon Valley: "'Only the paranoid survive.'"
"[Zuckerberg] was looking at the future saying, 'Hey, Facebook is great but we got to do other stuff to stay ahead of the game. I'm losing some of my younger followers. What can I do now.' And he made a big bet," Barrett told CNBC's "Squawk Box."
The Facebook-WhatsApp deal is mostly stock "so they're not wasting a lot of cash on it." Barrett said. "They really needed a communications play."
He noted that WhatsApp's announcement Monday that it plans to get into the "voice business to compete with Skype and Microsoft and other communication companies."
"In social media, the whole issue is the number of subscribers, the number of customers you have," he said. With more than 465 million monthly active users on WhatsApp, "you can't sneeze at that."