Of all the brands using digital and social media to compete for the attention of China's 668 million internet users, Durex has emerged as the master of witty, shareable content. That's partly because regulations on traditional advertising in China forced consumer goods giant RB to get creative after it took over Durex in 2010. "Historically, TV advertising has been banned for condoms," said Ben Wilson, RB's marketing director for China. "When we first started, it was a huge challenge to our global model, which was TV-driven, and that forced us to be much more digital."