On Friday, Google quietly announced City Experts, a new program that offers perks to those who frequently review local restaurants, bars, and businesses in Google Maps. To be a City Expert, you of course have to be a Google+ user, have to have written at least 50 "high quality" reviews, and then maintain a pace of at least five reviews a month to stay in the program. The push comes after Google's recent redesign of Maps apps on Android, iOS, and the web. A key part of the new Google Maps is prominent placement for Zagat and Google+ user reviews in Maps search results.

So, what makes a review City Expert quality? "A high quality review is usually three to four sentences long and contains specific, helpful and balanced information about a particular business," Google says. Those who register for the City Experts program will receive an invite to a Google+ Community of other reviewers if or when they have written 50 reviews in Google Maps — these reviews show up in the Local section of Google+ too. Once in, Google says it'll send out a monthly email that offers local discounts, contests, free Google-branded merchandise, and invites to special events in their area.

For now, Google is only accepting City Experts in Austin, Chicago, New York, Phoenix, Portland, Raleigh-Durham, and San Francisco in the US. In the UK, the program is open to Google+ users in Bristol, Edinburgh, London, and Manchester. And it's also available to those in Sydney, Australia, and Tokyo and Osaka in Japan. Google says it hopes to expand the effort to more cities at a later date. For now, Yelp remains the preferred place for those who like to sound off in local business reviews. But clearly, Google is trying to lure local critics over and justify the real estate it's given business reviews in Google Maps.