Pinterest and affiliate marketing have not always been on the best of terms.
At one point, Pinterest banned all affiliate programs from their website but have since made a small retraction and they now allow only a few select affiliate programs on their website.
This may not seem like a big deal, but trust me; it is.
Instead of having to send people to your blog first and then convert them from your blog to an affiliate program (with the hopes of making money), you can now send people who are on Pinterest straight to the affiliate program you are promoting with the use of an affiliate link.
Given the huge viral potential of Pinterest, a pin with your affiliate link embedded in it can easily be shared with millions of people and yes (albeit small) a percentage of that millions of people can eventually make you money.
As I said though, only a few affiliate programs are allowed on Pinterest and to find out which ones, take a look at this great video I found on YouTube that will share all the details you need to know, including how to use affiliate links on Pinterest.