Aided by the Winter Olympics, total advertising expenditures increased 5.7% in the first quarter of 2014 to $34.9 billion, according to data released today by Kantar Media.   “The Winter Olympics delivered its expected windfall in the first quarter, adding about $600 million of incremental ad spending to the marketplace. But the nature of the event is that this money is narrowly distributed and doesn’t benefit all sectors of the market,” said Jon Swallen, chief research officer at Kantar Media N...