It is widely understood that reviews are of high importance.
Having many reviews will increase the position of your Local listing on Google.
People routinely use reviews to help evaluate a product or company.
There are many known instances of loading up competitors listings with phony bad reviews.
So an important part of any Internet Marketing strategy is to work on getting reviews posted on Google Places and elsewhere, AND to monitor your presence on the Web.
Automated review selection by search engines can lead to some horrifying results.
Here’s a good article on the subject (additional info in the comments).

When Google Review Clippings Go Horribly Wrong