MADRID -Facebook’s $19-billion takeover of smartphone messaging service WhatsApp staked the social network’s place in dramatic fashion as a pivotal player in the mobile world.

The US social networking giant’s 29-year-old founder Mark Zuckerberg snatched the limelight ahead of his debut as the star speaker on the opening day of the February 24-27 World Mobile Congress in Barcelona, Spain.

Overshadowing even the hotly anticipated release of Samsung’s new Galaxy S5 smartphone at the mobile fair, Facebook’s cash-and-stock deal reflects a structural shift towards mobile by Internet and related technology industries.

For Facebook, smartphones and tablets represent a fast-growing and crucial source of advertising revenue. Microsoft sees its future in mobile, too, with a 5.44-billion-euro takeover of Finnish group Nokia’s loss-making mobile phone division. Sony, which may launch a new Xperia smartphone at the mobile fair, announced this month the sale of its stagnant PC business to focus instead on smartphones and tablets.