For small businesses, reviews are worth gold. Not only do they lead to more business, more revenue per customer, and higher profits, they also lead to better SEO. You see, the more reviews you get, the more Google will show your profile in searches. Remember, their goal is to ensure that “searchers” have a good experience, and a lot of good reviews is surely a good indicator that people visiting your business will have a good experience. It also helps deflect the impact of the person who will inevitably leave you a bad review one day. If you only have one 5 star review, and someone gives you a 1 star review, now your average is 2.5 stars. If you have twenty 5 star reviews and someone leaves you a 1 star review, your average is still 4.8 stars.
The folks at Invesp created a great infographic about the importance of reviews. It is based on a variety of studies.