Needless to say it's a great social network for anyone who is in a visual niche. It can also be good for more verbally oriented subject matter. But if you are into, say, political blogging, you'd tend to get more out of Twitter and Facebook.
Not only is Pinterest a very pleasant site to use, it tends to do well in Google searches. You'll notice that if you search for certain keyword phrases, every now and then you'll see pins and boards appearing in results. This happens more frequently if your search is related to niches that Pinterest is ideal for such as fashion, beauty, cooking, interior decorating, etc. But it still performs strongly across other fields of interest.
Basically, if you can take a pretty, crisp photo of something, give it a specific name (eg, brand, model or designer) pin it to a relevant board in an account that has lots of followers and activity around it, there's a reasonable chance that it will appear fairly high in search engine results.
It can also punch above its weight when it comes to local SEO. I've learned this directly since creating a Pinterest board related to Perth business. Lately I've been searching for some of the business names listed on it and I've been pleasantly surprised at how high those pins are ranking in searches. They're generally not on page one. But a few of them are around the top of page three. Now these are just photos I took myself, named and uploaded. And that board doesn't have many followers or activity around it at all. But it still earns those positions.
With this in mind I've realized I can use this Pinterest board like a local blog. It will be a long slow process, sure. But the more Perth businesses I add, the more these pins will rank for local searches. More locals will see it and some will click through to my site. This added to the fact that there are a growing number of Perth people active on Pinterest make it a worthwhile activity. They'll be using its internal search function to find local stuff, too. And, as with all social networks, that's like a mini-Google in its own right.
Now, this SEO aspect is something that other social sites don't have to the same extent (except perhaps Google Plus). Facebook pages, for example, can appear in searches. But getting high positions in them is much harder than with Pinterest. That's why I think adding this visual string to your local marketing bow is worthwhile.
Speaking of Facebook: With all this visual content on Pinterest, you can post it to Facebook too, and get more mileage out of it that way.
And not just on your own pages. You can also share relevant pins and boards on the Facebook pages of other people and businesses. This is a great way of getting on their radar that is completely non-spammy if approached correctly.
Here are a couple of tactics I've been using that work well. Firstly, my FB page for this site is connected to those of many Perth cafes. So I've been sharing some of the pins I've been collecting on my coffee humor board. They appreciate it, with these updates getting regular likes from the page owners.
Another angle: I go to the website of a local business that I've liked on Facebook (as my page). I pin an image from their site on the relevant board. This helps them a little bit for SEO because even though it's a nofollow link, Google still sees it. It's also a bit of free advertising for them because people can click through from the pin to their site. And that does happen occasionally. So, it's definitely helping them.
So, after I pin the image I tell them via their page, including a link to the board. A high proportion of page owners have liked these updates, and/or said thanks. A couple have even shared the board themselves as a page update in itself. So it's definitely a win-win.
No matter what field or location you're in, you could use Pinterest in the ways described above. The trick is finding your own unique variation on them.