We have not launched yet, so we have no customers. We are a B2B company.
I have used www.kickfu.com for B2C surveys: it's cheap and quick. What are the best options for online B2B surveys?
I'm not sure what really separates a B2C from a B2B survey, but I've used surveymonkey.com (now a part of mailchimp, I think, which is another great service) to send B2B surveys out.
The heavens didn't fall, and I got some great feedback that helped shape our product development, so it should be safe for you to use :)
You can have a look at:
Zoomerang, Survey Monkey
Google Forms can also be used Conduct Surveys. It will be simple and also the link will be of google domain which may adds a trust factor for some.