How can a consultancy use social media to their advantage?

I am looking for some help on how an international consultancy firm that assists companies to set up business in a foreign country can use social media. Do you see social media having a benefit for them? What do you could possibly harm them? How can they go about maintain the very fine line between social interaction and professional interaction? The fact is that they deal with information, connections and other services of that nature instead of a consumer product. Thus I need some insight into strategies and platforms that could benefit them and how to maintain their audience interested.

Thank you.