I installed it, created an account and there is nothing about a license key anywhere in my 'account' and no email. But there is a pricing structure for spam comments which is incredibly difficult to understand.
From what I can see, there is 5 free 'non-spam' comments a day covered. What does that mean? Well, I don't much care since I didn't get a key. Now I have to worry about spam from THEM I suppose.
No instructions to close my account. Keep looking.