Facebook (META -3.56%) posted strong quarterly results on Wednesday, but some worrywarts are pointing to a 15% decline in desktop advertising revenue. This remains the social networking giant's biggest business, and on the surface the concern is understandable.

However, overall revenue did soar 38% during the quarter. Mobile advertising -- which didn't even exist a year ago -- has ballooned to make up nearly a third of Facebook's advertising revenue. 

In this video, longtime Fool contributor Rick Munarriz points out how this shift in strikingly similar to what has been happening at Netflix (NFLX -8.71%) as DVD-based subscribers have fallen off over the past two years. Streaming Netflix subscribers have more than offset the slide in mail-based rentals, and now mobile advertising at Facebook is more than offsetting the slide at Facebook.com.