I've been in the business listing (rating and reviews) biz for 6 years. Get out now.
Unless you can compete with the big guys - even your small local niche directory is going to be destroyed. Google is now the business listing king and all that juicy long-tail traffic from people looking up local businesses (Some of you know what I'm talking about) is going to all be going to Google or the big guys.
So, if your business listing site is relying on organic Google search to be successful - I'm sorry (boy am I sorry) that is not going to happen for any length of time past the honeymoon phase.
In other-words, even if you have a far better niche directory for the subject and location than the big guys with far better local content - Google does not care. You're done.
Just like Google scraping the fresh/not fresh content from a big movie review site - they are now going to be the curators of business listing content.