How to make customer easy to give feedback <ul>
<li>Set up a customer advisory program</li>
<li>Conduct regular surveys</li>
<li>Encourage responses to your email newsletters instead of having the reply-to address go to an unmonitored or nonworking email address</li>
<li>Publicize email addresses and phone numbers&#8211; customer service, technical support, and even your own personal email address</li>
<li>Better yet, make those phone numbers toll free</li>
<li>Hand out business cards at trade shows</li>
<li>Start a blog and allow comments</li>
<li>Add a feedback link on every page on your web site</li>
<li>Monitor and post to relevant discussion lists and message boards</li>
<li>Encourage your sales staff to provide your contact information directly to customers who want to provide more input</li>
<li>Contact people who are talking about your product already &#8212; in blogs and on mailing lists &#8212; and follow up to get more feedback</li>
<li>Every time you talk to a customer, ask them to refer you to someone else who can give you additional feedback, and encourage them to pass your contact information along</li>
</ul>- http://www.goodproductmanager.com/2007/03/15/make-it-easy-to-give-feedback/

Other related blog - http://headrush.typepad.com/creating_passionate_users/2007/03/user_community_.html http://www.taylor.se/blog/2007/06/13/my-rules-of-feedback/

Some will think non-feedback, uncall feedback are more important - http://www.infoq.com/news/2011/04/non-feedback-uncalled-feedback