What does this do that firefox bookmarks can't, except showing a thumbnail? I know "folder hierarchy" sounds so 1990s, but still.
It saves not only bookmarks but associated content depending on page type. If it's an article, it will be cut and saved with the bookmark. The same applies to video, photo and presentations. Also you can share some collections of bookmarks. In future update you can also collaborate with colleagues and friends.
Ah, that's actually quite nice, although I suppose it only makes a copy of the text, not of the video & audio, right?