Today, more consumers than ever before are reading online reviews before selecting a local business to make a purchase. It is therefore important that your business reviews are visible in high ranking positions on the review sites your target customers are most likely to visit and search on and on the third-party review sites that almost always appear in the first two search results pages at Google, Bing and Yahoo on a local search query. Because of its dominance it is most important to get reviews on your Google+ Local page. Google also recently announced a new AdWords extension that allows you to add third-party reviews dynamically into your ad copy of your AdWords ads.
It is more than likely that Google, Bing and Yahoo are using the presence of customer reviews as a general ranking signal for the algorithm that determines the ranking positions of a site in the local search results. For instance, in ranking your local business, Google takes into account the quantity of reviews you have earned around the web. There is evidence that the number of reviews your business earned on its Google+ Local page influences the ranking position on the local search results more than reviews you might have earned on other review sites.
The most challenging task is to get as many reviews of your business as possible on your target review sites so that they show up in high ranking positions. To accomplish this you need to find a way to get your customers to leave reviews on the target review sites, including Google+, Yelp and others. Note however, that it is against the policies of Google and Yelp to solicit customers to write reviews or to offer money or products to write reviews.
This infographic, designed by Local Visibility Systems, is a good starting point in determining which sites would be most appropriate for your customers to write reviews on.