The runners-up were 15-year-old Pakistani activist Malala Yousafzai, Apple CEO Tim Cook, Egyptian leader Mohamed Morsi, and Higgs boson physicist Fabiola Gianotti.

Here's the story by Michael Scherer of Time.

It seems that re-election was a big part of the decision to choose Obama:

"It could be measured — in wars stopped and started; industries saved, restructured or reregulated; tax cuts extended; debt levels inflated; terrorists killed; the health-insurance system reimagined; and gay service members who could walk in uniform with their partners. It could be seen in the new faces who waited hours to vote and in the new ways campaigns are run.