Every bride uses Pinterest (and now most wedding vendors and bloggers).
My mother-in-law uses it every day to plan all her home remodeling projects and she's 60-something.
Any study covering all the brides situation to qualify that comment? I attended three weddings recently. Not one was on Pinterest, all were on email rather.
I can't believe you just asked me for a study based on that comment (where "every" is clearly hyperbole). Let me Google it for you (EVERYone uses Google).
Look at that ... 70% of women use it for wedding planning BEFORE EVEN GETTING ENGAGED
http://www.huffingtonpost.com/2014/07/25/wedding-survey_n_56...
Brides typically use it to decide what they should wear, what their wedding party should wear, and what decor should be used at their reception etc. See for example [1],[2]. Note that [2] has 4 million followers, for that board alone.
If it's studies you want, then something like [3] shows just how much traffic Pinterest drives: much, much more than Twitter, and second only to Facebook in terms of social sources.
It's not typically used as an organization tool in itself.
[1] https://www.pinterest.com/categories/weddings/
[2] https://www.pinterest.com/explore/wedding-ideas/
[3] http://www.businessnewsdaily.com/7356-social-media-marketing...