Yes, you can use QQ for business marketing. QQ is a popular chat and social media platform where you can talk to your friends, your coworkers, or your business partners. As long as you are careful to go through a third party service for QQ chat, then QQ can be a great tool for marketing, much like how people use Facebook or Instagram to promote and further their business.
Many people in China do not own cell phones, so QQ has risen in popularity particularly among those people. Today QQ has over 800 million users, so it is definitely an important business strategy to use this platform to help promote your services.