Instagram: Users share their photos and videos, it is social networking service. Instagram is sharing more about personal experience things with people who follow each other. This is best for sharing authentic content and creating brand awareness.
Pinterest: Users share their photos and videos, it is social networking service. They can create share collections. Also, they can search particular content or products, and it is linked to the source of the image, usually external site. Pinterest is also a proven sales generator for retail business.
Tumblr: It is not just only sharing photos also can publish short texts, images and videos. It is similar to traditional blogs. It goes into more detail about information, so that it can have strong marketing power because people are sharing not only their simple image but also their opinion and idea through this.
Constant Contact 1996, United States, California, viewed 13 September 2014 <http://blogs.constantcontact.com/product-blogs/social-media-marketing/difference-pinterest-and-instagram/>