The secret to Yelp! is to get good reviews. Send some of your recent customers to Yelp! and ask them to review your business as well as share their experience. I recommend that you try and get two Yelp! listings a month. In just one year, you will have 12 reviews. In two years, you will have 24 reviews.
If you have not already claimed your listing at Yelp!, click on over and do it today at https://biz.yelp.com/support/claiming.
At the time of this writing, Yelp! offered an “upgraded” listing that gives you more control of your business listing and more management options for $75/month. It will also remove the competitive listings on your page when people are viewing it. Yelp! provides pretty good analytics each month. If you are not happy with the visibility and traffic they deliver, simply cancel your program.