Congratulate LinkedIn on its work anniversary! Next month the business world’s favourite social network will turn 22. The 1.1bn users of LinkedIn—which is a year older than even Facebook—can celebrate two decades of humblebrags, motivational quotes and automated congratulations from long-forgotten acquaintances. Microsoft, its owner, can meanwhile toast a canny acquisition. Since the tech giant bought LinkedIn eight years ago, for $26bn, the platform’s annual revenue has grown from $3bn to $17bn.