It's lame, but they've done an amazing job of making women want to spend money - on decor, on clothes, on new hairstyles, on DIY projects, on food...it's one giant WANT spree.
It doesn't seem to convert nearly as well as ThisNext and Kaboodle did in their heyday (before they redesigned the product pages and de-emphasized the links, cracked down more on promotion, etc.). I think that's because the older social shopping sites used to get a TON of search engine traffic from specific product searches that went to individual product pages, while Pinterest seems to get a lot more random browsing. It also seems to have a lot more non-tech-savvy users (like my grandma, who loves it) who may not be so quick to buy online.
I haven't done a TON with it, but I've played around with a few accounts and some themed boards that got a lot of traffic and a relatively small number of conversions (given the traffic coming through). Basically, I would just pick a random theme - geek boyfriends, colorful kitchens, boho bathrooms, bird-inspired decor, whatever - and then build a board that included lots of links to relevant datafeed blog posts containing affiliate links, or direct affiliate links where possible. I'd usually add in a few totally non-commercial things just to make it look "real". It worked well enough that I'm going to test outsourcing it, because it's definitely not worth my own time to do it, given the results so far.