Martin Sorrell, CEO of advertising giant WPP, used his keynote presentation at this year’s GSMA Mobile World Congress to declare that “in terms of revenue generated through apps, we are still only touching the tip of the iceberg. The opportunity for growth is huge as smartphones get into the hands of masses.” He noted that the ability of mobile apps to provide advertisers and publishers with a method to deliver targeted content, using personal data and location information to improve accuracy, “is the holy grail that we as advisors on behalf of our clients are looking for.”