Microsoft’s share of US digital ad revenues will fall from 6.2% last year to 5.9% this year. Microsoft’s $2.53 billion in ad revenues, which include advertising not only from the company’s web properties, but also from Xbox and Skype services, will grow to $2.87 billion by 2015, though not fast enough to hold or increase market share. Twitter will take in a comparatively small $420 million in US ad revenues this year, eMarketer estimates—about a 1% share.
On a worldwide basis, Google and Facebook are also the top two ad publishers, with 31.91% and 5.64% of the market this year, respectively. Read the rest at eMarketer.