Her promotion to head of advertising puts Wojcicki at the helm of a business that generates 96% of the companyís approximately $29 billion in revenue. Part of CEO Larry
Pageís inner circle, sheís also picked up responsibility for engineering for the ad team -- a key role at a company where engineers are king.
The list is compiled by FORTUNE editors, who consider four criteria: the size and importance of the womanís business in the global economy, the health and direction of the
business, the arc of the womanís career (resume and runway ahead), and societal and cultural influence.