There are a few different reasons that your business might benefit from Pinterest. They are:

Demographics

Pinterest users have a unique demographic profile. Unlike virtually every other social media network, Pinterest users are mostly women. Overwhelmingly so. Specifically, Pinterest users tend to be middle class partnered mothers with kids, aged 25-34. You can see a more specific demographic breakdown here.
This is key demographic for many industries. It is also a demographic that, in the world of social media, is virtually unique to Pinterest.

Content format

Pinterest is a photo board. People post photos. Some get popular, some don’t. As such, it is a great place for businesses that turn out a lot of interesting visual media. Specifically, businesses that do well on Pinterest have visual media that is not only interesting in and of itself, but also that works to increase brand awareness.
Fashion and clothes do particularly well on Pinterest, because the entire sales pitch is visual. Food brands also do very well. This is due to a known psychological tendency for people to prefer pictures of people and food to pictures of almost anything else.

Good Brand Image

Like all social marketing sites, people share companies’ content partially because they think it looks good to be associated with that company. While your company is selling itself to users, users are using your company image to sell themselves to their friend networks. As a result, socially-conscious, cool, or rebellious brand images help businesses on Pinterest to gain followers.

Online retailers

Pinterest has a smaller user base than Facebook. Users are spread farther apart and are less likely to be in your company’s immediate vicinity. It is also more challenging to target specific geographic areas than it is on Facebook, though not impossible. All these factors make Pinterest less appealing to businesses that only operate out of one or two storefronts.

In contrast, large national or multinational brands do very well on Pinterest. They are able to market thousands of storefronts from the same follow page.

However, there is also opportunity on Pinterest for online retailers to do well. Pinterest content has a higher click-through rate than Facebook content. Exposure on Pinterest means more. Coupled with a strong landing page and a good online product, Pinterest can return very high sales for your dollar.

Businesses with interactive ad campaigns

Interactive games, contests, and apps hit a peak a while back in Facebook. There were just so many clogging up news feeds that Facebook was forced to start punishing it with the EdgeRank algorithm.
However, that point has not yet passed with Pinterest. Contests and games spread like wildfire, and are not nearly common enough to be seen as boring or spammy.