It’s all about context
The question “What is good communication?” means nothing without context.
Who’s talking, who to, and what are they trying to say? Communication is basically the conveying of information (between you and an audience). Good communication is where what you convey is understood.
In business, everything you say and do is part of what you communicate (to clients, customers, and competitors). To communicate effectively you have to be consistent: say what you mean and mean what you say.
Don’t pretend to be something that you’re not. Tell the most engaging and truest story about yourself — based on what you do and what you’ve done. Be as clear, open and direct as possible in all your communication (including marketing and customer service). The experience someone has dealing with your company IS your company. Be honest. Be consistent. Be yourself.
Good communication is also a two-way street. It’s about being available to your audience, listening to what they have to say and being responsive to feedback. Good communication isn’t just about broadcasting information — it’s about the conversation. (Eg. Twitter)
Monitor the conversation your audience has about you, but don’t interrupt. When your audience engages with you, pay attention and be willing to respond. Keep your promises.
Listen and be sympathetic to any feedback you receive — try to understand your audience or see things from their perspective. This level of awareness, receptiveness, and responsibility makes good communication possible.
The best communication is about being present and available to your audience.