Sometimes, it can be helpfull to know what people are thinking about your website. You may want a survey about a specific subject. Or people may want to rate your site.
Everything is possible with polldaddy. You can even make a popup survey, poll or rating with my popup post: how to make a popup
1) Sign up to polldaddy at http://polldaddy.com/signup-free/
2) go to your dashboard and create whatever you want
3) Check your dashboard for the created content
4) you can choose to embed it in your website (or link it to the polldaddy link)
5) check the results
PS: to integrate it in a popup for wordpress, check the link above. To integrate it in a post, you can also use the embed code, or use the polldaddy plugin.