Google has quietly launched a new local program called Google City Experts. They announced it on their Google Local New York Google+ page.
In short, it gives those who are active Google Maps reviewers, i.e. users with at least 50 high quality reviews, and at least 5 reviews in the current month, special perks like event invitations, custom swag, special access to contests and more.
You can apply to be a “Google City Expert” over here.
Google said those that are accepted get access to:
Access to fun, exclusive events in their local areas
Free custom swag
Special online recognition
I guess this will help encourage good reviewers to review more.
Forum discussion at Google+.