Alphabet's Google unit has begun trying to do to Facebook what Facebook has largely done already to Snap: stifle its user growth by aping its features. Just in the past two weeks, Google has: Updated its mobile app with data and features that make part of it look more like Facebook's News Feed product. Google calls that portion of the app its "Feed."

Rolled out "SOS alerts," tools that deliver emergency information to users of its Maps and Search apps facing a crisis. It comes nearly three years after Facebook introduced its "Safety" feature, which lets users check in with family and friends after a terrorist event, natural disaster or other potentially dangerous situation.

Begun pushing notifications to users of its desktop Gmail application suggesting they try using the company's mobile app. (See notification window below.) That marketing technique is notable because it is similar to the one Facebook used to push tens of millions of its users to try Instagram, a service which grew by 40 percent to 700 million users between June 2016 and April,2017.

These moves suggest that even though Google has largely abandoned hopes of catching Facebook with its own social network, Google+, it still believes there is value in aping individual Facebook features. That's not a bad idea, given how profitable and fast-growing Facebook has been. "There's no internet company that's been better (than Facebook) over the last five years at delivering consistent, strong growth across its (financial) metrics," says Scott Kessler, director of equity research with CFRA, a firm which has "buy" ratings on shares of both companies. Google's updates to its mobile Feed, which now includes local data on weather, events and restaurants along with articles from its media partners, are especially notable because they reveal the company's biggest fear: That a growing portion of consumer internet activity is moving away from searching for things online to finding them via friends, family and favorite publishers on their social networks. "The world is moving away from the notion of traditional search," Kessler said in a phone interview with CNBC Friday. By giving mobile app users relevant, bite-sized information even before they type a query into its search box, "Google is trying to make the search experience more dynamic," Kessler said. "They have a lot of data and Feed helps them tie it together."

Different price trajectories