Pinterest is free to use for both individual people and businesses. If you have a personal account, it won't cost you anything to sign up, nor does it cost money to use any of the website's functions. A business account, which includes special promotion and analytics functions, is free as well.
Since we know Pinterest has very similar characteristics of Google I think it is at least important to have a consistent presence on the platform. So the short answer is yes. Pinterest is definitely worth your time.