I have to code this Pinterest Bookmarklet all the time, which means going through and adding it to each of the template pages that I client needs. This plugin let's me easily add it to the areas I want (e.g. categories, single posts, blog page, static pages, etc...) without having to fight with where it should and shouldn't show.
As a plugin developer myself, I appreciate it when people make something simple, lean and with just enough features for it to do what you need it to do. Thanks for a great plugin.