Google Surveys is a pretty simple concept where companies will submit their surveys to Google and through various publishers, the companies can get responses about their new products or services, which would help them to serve better.
The company creating the survey will pay Google $0.10 per response (for a general survey) or $0.50 per response for a demographically targeted survey (like when they want to target residents of New York who are in the 18-24 age group).As you can see demographically targeted surveys can fetch you more, so if you have a good micro traffic site, then you can make bundles of cash with Google Surveys.
Publishers can Register here for Google Surveys.
Google Surveys follows a similar selection and execution pattern as Google Adsense.