Facebook-the-(news feed/profiles/messenger) are just the most successful applications on Facebook-the-platform. Marketplace and Dating are just continuations of

Facebook-the-(news feed/profiles/messenger) are just the most successful applications on Facebook-the-platform. Marketplace and Dating are just continuations of this trend. The strong platform underneath is what makes Facebook successful but conversely, they need these value-adds to keep their platform from crumbling beneath them.