[SteveC]

Comments could backfire on you. What if you have paying subscribers who start recommending your competitors or free/cheaper alternatives to other paying customers. How do you deal with that. Deleting the comments risks alienating customers. Removing the comments feature would annoy all the customers who now enjoy it. Doing nothing will mean you're effectively giving free advertising to competitors.

[LoonyPandora]

Make sure your product is better than your competitor's. You shouldn't be scared of a customer doing a fair comparison of your product against someone else's.