So I'm located in Green Bay Wisconsin. Admittedly not the center of the technological Universe however, when I am speaking to business owners I often filled questions regarding Yelp such as:
Why should I care?
Nobody uses it anyway.
I'm not really certain of the statistics of Yelp users in my area but, one thing I am very certain of is that it is extremely important for businesses to take it seriously. That's because Yelp is a foundational database background for business listings in Apple products, Bing, Yahoo and others. Perhaps you even recall when Google showed it Yelp reviews on their business listings. They may not do that anymore but I guarantee that it is part of their algorithm when ranking businesses and websites.
Don't believe me? Whip out your iPhone, say “Hey Siri - find me a good plumber” and see what comes up.
Do the same on Bing (23% market share) and Yahoo (12% market share)...
I often find myself saying sometimes you advertise to the customers and sometimes you ever ties to the search engines. Make sure you do a good job for both.