Pinterest has recently updated their site design and some other functionality and due to this some SEO benefit has been lost or restricted. Previously one used to get a dofollow backlink with every image pinned but now it’s no longer working.
Now you get only a nofollow image link. But I don’t see anything bad in that. A link is a link whether the attribute is set to dofollow or nofollow and the best part is that these links aren’t going anywhere. So in some way or the other you are getting a link back to your page and to me it’s natural. So keep pinning and get some backlinks.
Pinterest also provides tools specifically designed with businesses in mind. Businesses can create special pages for promoting their products and services, and these pages serve as a virtual storefront in a similar way to business pages for Facebook, Twitter and various other social networks.