Yelp is a great way to find local businesses and to get trusted input from real peoples reviews. As a business and Yelp page owner, one thing you may be looking to do is gain more positive yelp reviews. Whether you ask customers or friends to write a review, it is not a certainty that yelp will recommend and display these kind words about your business.
Yelps biggest goal is to provide helpful, quality, trusted and reliability information to the yelp community. They do this by recommending and showing reviews from users that have the biggest profiles and largest network. Yelp will often not recommend and hide a review from a user that has just joined Yelp and when they have an unfinished profile, no friends and just one review.
Every yelp review is run through a recommendation software for quality, reliability and user activity. The more active a user is, the more yelp will recommend a specific review.
Next time your yelp reviews drop from 5 to 3, now you know why! Yelp has also developed a video with more information on their recommended review system.