The issue is the feedback is important and urgent to you, but not to your target market. They've been surviving to this point without your idea, so any requests go to the bottom of the pile. Plus "A million other people must be answering this" is the response people give to a bland mass email.

Information interviews are some of the most important things you can do, and I've written several posts about them here:
http://www.salestactics.org/?s=information+interviews

Finding out the truth of what your target market is really thinking is the number one thing you can do.

Don't leave it to email. Do it live; people will be more flattered than you might think to be asked their opinions--provided you ask on an individual basis rather than what looks like a mass message.