Pinterest content is being crawled and indexed by Google, therefore it will impact your SEO rankings.
Pinterest is unique because it is the only social networking site focused solely on sharing images.Pinterest allows you to achieve instant traffic from real people, and these are users that have a genuine interest in your offering.
put a "pinterest" button on your website then as much sharings google will identified of your specific page on pinsterest will help in your site's seo.
according to latest google updates the search engines now also consider how users share your content on different social media so as much sharing you got on pinterest, google plus, facebook, twitter etc will improve your site's seo.
Pinterest can also show the price tags on the pins of the products you sell from your online or offline stores. It gives huge traffic to the blogs and small websites which have good content with excellent image selection.