Great customer service

It's both good communication skills and product knowledge.. Good communication skills is a must in order for agents to build rapport to our customers and so that our customers could also understand us well - to avoid confusion and irritation on the customers side. Product knowledge (not just the scripted type) is also important for good cs experience, if we understood well our product we'll be able to deliver and convince our customers. We will also be able to make them see clearly what's the real purpose of our product and how it works. I'm an outbound agent so it's really scripted account, i don't do it in verbatim..memorizing our scripts is far too different from analyzing the script and therefore knowing our products well.

Both communication skills and product knowledge will make good customer experience. However, If I would put myself on a customer's shoes I would rather prefer an agent who knows how to communicate well because everything can be solved if we understand each other.

It's both. But being in a call center industry, a good communication skill will be the foundation of a great customer service :-)