Create "Whitelist" filter by tag for submitting questions to the community, not only a "Blacklist."

I love the idea of having a community of customers help answer other community questions. However, I want customers to be able to "opt in", instead of just being emailed because they had purchased the product recently. I can assemble a group of dedicated customers who want to be on this "team" and I would like the emails sent to them, and not just any customer who bought the product within a certain time frame. I believe Amazon has an opt-in process for this.

It would be extremely helpful to have a "Whitelist" feature or even better, the option to filter customers by tag. That way I could add customers to the "community" as they opt in, instead of requiring them to opt out after the first one. Our customers get a lot of transactional and marketing emails, and I hate to send them more because they will start glossing over them. This filtering feature would enable me to target questions just to specific repeat customers who I know are dedicated and knowledgeable in answering them.