Digital advertising is growing as quickly as the medium it inhabits, and companies investing in digital advertising are seeing great returns. Major companies in the captive advertising market—AOL, Yahoo, Facebook, Google, Microsoft, Twitter, Apple, and IAC—are expected to see solid growth in the market, with varying levels of success depending on the specific type of advertising. Google continues to hold significant market share in search advertising, while Twitter and Facebook are poised to begin taking more market share from Google in display advertising. Mobile advertising promises to be a significant market for all companies.