Coca-Cola is considering a monster purchase to get a bigger foothold in the world of energy drinks. The largest soft-drink company on the planet is in talks to buy Monster Beverage in what would be its biggest brand acquisition: Monster has a market capitalization of $11 billion, and the company is growing fast. At $1.7 billion, its 2011 annual revenue marked a 31% increase from 2010, and its fourth-quarter numbers were equally impressive, the Wall Street Journal reports. But the matter isn't settled: Coke may see Monster, which trades at 30 times its estimated 2012 earnings, as too expensive. The company's stock price has nearly doubled over the past year. (More Coca-Cola stories.)