From DSO News:
Your staff should encourage every patient to leave a positive online review. Get a poster printed, frame it and hang it on your waiting room wall inviting patients to leave a positive online review. Have a framed 8.5″x11.5″ reminder hung next to your door that patients see on their way out. Get postcards printed with all of the ways to leave an online review and give one to each patient upon checkout.
Online patient reviews are powerful. As recommended in the linked article you want to encourage patients to post positive reviews. However you do not need hundreds of reviews and you do not need a constant flow of new reviews.
If you have 8-10 reviews with a 4.8 or better rating and get one new review each quarter (four a year) you are golden. However to get four a year you need to ask forty or more people.
You may need more reviews if you start with a really bad one The best way to deal with a negative review is to overwhelm it with positive reviews. If you get a one star review you will need four five stars to get your average over four.
If you are consistently getting three stars or less you need to fix something. You or the staff is messing up and it will devastate you in the long run. Even people who start with a good personal referral will be put off of they find you have poor reviews.