Eye contact is pretty useful. You can read a lot about a person by making eye contact with them (body language, facial expression, non-verbal things). It's also a good way to say, "Hey bitch, pay attention to me. I don't want to waste my time talking to you only to have you not listen." However, some cultures find maintaining eye contact as rude and defiant (like you're challenging them), so be careful.
I prefer not to use it though, it's extremely taxing on your energy. I only make eye contact during the initiation of the conversation and when you say something interesting.