Using surveys can provide the following benefits:
Easiest to quantify the data
Data easily summarized and reported
Time-effective for use with geographically dispersed or large numbers of people
Questionnaires can easily be sent to people through mail or as part of a magazine or other media
Relatively inexpensive
Incurring some costs for a well designed survey will be money well spent for reliable data
Questions can be asked in formats (multiple choice, ranking, etc.) that provide for easy tabulation and summarizing.
Opportunity for expression without fear of embarrassment (anonymity)
Anonymity can help provide more truthful and thoughtful answers.
Relatively bias free
Have editors review the instrument to remove as much bias as possible
Permit people time to think about answers
While there are insights to be gleaned from spontaneous answers, thoughtful answers will usually be less colored by emotion.
Questions can be used or modified from other instruments
Questionnaires can be compiled from a variety of materials.