Is a survey a good way to get user feedback?
answerly: Check out usertesting.com.  I have had a lot of success using their service.  For about $19 you get a screencast and talk track of a user trying to complete certain goals (that you pre-determine) on your site.  Its not perfect, but it is a great way to get insights from 3-5 users that you can then use to create a larger survey for the rest of your user base.My experience with surveys is that the more open ended you make them, the less valuable the feedback is.  I would try to come up with 4-5 questions tops.  Its a good idea to try and figure out what the theme of the survey is upfront (i.e. on core thing you want to be able to figure out from the survey data).  Some businesses try to cram too much into a single survey- I have had more luck with shorter surveys more frequently than less frequent long surveys.  Also, multiple choice and "rate on a scale of 1-10" questions have worked better for me than open ended text boxes.As far as the audience for your survey, unless you have a very large user base you should send it to everyone.  Responses rates on surveys tend to be pretty low and you want to make sure you have enough data to draw conclusions from.