China’s online advertising market sits somewhere in the neighborhood of $50 billion and growing. The market is dominated by China’s top online firms, including online retailer Alibaba and web services giant Baidu. But the country’s large market size, coupled with a rise in consumer spending over the past decade, has attracted online giants like Facebook, Google, and Amazon to compete for advertising dollars. Tencent, however, may be considered a sleeping giant of China’s digital ad market that’s just now getting out of bed. The company, which was founded in 2004, is comprised of seven business units under the umbrella of Tencent Holdings. It operates two social networks, WeChat and QQ, alongside a gaming division and a few online video services…