We could define cultural fluency as the ability to easily and naturally interact with people from different cultures, picking up the nonverbal and non-linguistic information, and giving relevant and genuine reactions. Briefly we could say that cultural fluency is always feeling at home in the given context of a culture.
Business may be business, but is still conducted by people. So when aspiring to maintain a fruitful business relationship, being able to connect with people on a real, human note is crucial. And when travelling to a new country, or working with people from different cultures, new challenges arise. So get prepared for them, and do your homework in advance!
I recently read about a case when a business negotiator lost an important deal in India. The reason was that the partner had the feeling that she was rushing through the talks, while the negotiator was consciously talking and acting in that rhythm, because she wanted to be efficient, and not make the partner feel that she is wasting her time. This is a perfect example of how cross-cultural differences can affect business, and communication in the workplace.