Customer requirements / feedback gathering

Today, I have a question for you.

Assume, that you want to build up a new application which is very important to your company. The application offers one of your core services. Because of the importance of the project you would like to precedently collect some ideas, requirements, nice to haves, you name it from your existing customers. Additionally, you don’t have plenty of time.
Instead of putting out a boring survey offline or online, how would you proceed? How would you approach your customer to elicit worthwhile response?

What kind of means of Social Media would you deploy? Why do you think it could raise the interest of people working in Risk management? They tend to be pretty conservative.

Any suggestions? Feel free to leave your thoughts as a comment or mail to me at patrick(at)galig(dot)ch.

Thanks in advance…