Once you have good content, it is important to determine how and where to facilitate social sharing. The content that your subscribers might share on Facebook is not the same content, nor is it in the right format, that might be shared on Pinterest.
Make sure that your content is sharable and appropriate for each channel. Use quality photos for Pinterest, likeable content with engaging thumbnails for Facebook, and link shorteners for Twitter so people can retweet. It's all about the channel and making it easy for your customers if they decide to share your content.