Public opinion polls can help determine trends in opinions of certain markets and consumer groups. These polls tend to be broader in scope and can be used in combination with primary data you collect that is more targeted to your needs. Some research firms share their public opinion polling data freely online. The following represent a few firms with Canadian, American, and international perspectives.
Along with opinion polling data from research firms, these library databases are a great place to start searching for public polling data and may enhance publicly available data you find online.