We all receive questions from our target market in one form or another. The difference between someone who listens and responds versus someone who listens, responds and then creates is that the second person usually ends up with more sales.

You should never answer a question one-to-one more than once. If you are receiving the same question over and over, it is a clear indication that you need to create a resource (paid or free but preferably paid!) to respond to future question-askers.

If you can not act on each popular question right away, simply keep a list. I like to keep a swipe file in a private project in Basecamp, an online project management tool, where I simply add popular questions to a to-do list. This allows me to create something for the question in the future and just check it off when complete.

Alternatively, you could setup a free account at Formspring. Formspring allows users to ask you questions whenever they are struck with one. You can choose to respond on Formspring itself or you can choose to respond in a blog post OR, if the question is popular enough, you could create a product for it and point the question-askers there.