This only works for "pinners" who are following you, but are not following many other people, when your Pinterest board(s) are specifically focused on a product or service that you are trying to market. You might consider these pinners as having very refined and specific taste, because they are following so few people. Of course, this is not true in all cases. Perhaps they are new to Pinterest. But by viewing their boards, you will be able to make a determination regarding the level of critical thought and insight they have put into the pins they have chosen.
Within this context, look at the other people they are following. Are you pleased to be considered within the category they have chosen? What is the common theme? Do you agree with their focus of curation? In some cases, these pinners can help you better understand your brand, and how you might market it.
It would be very interesting to follow up with these pinners to better understand what they see in your brand and why they have singled it out.