Just works. There is a difference between "I don't want to save this, but I will get back to this later" versus "I have read this and bookmarked this for reference". While bookmarks solve the latter issue, one tab fills in the gap for the former. This is very useful to me and saves me from the bookmarks route where I am very particular about organizing my information for quick access. Also, it has a quick-glance friendly visual page view of everything, instead of a sometimes cumbersome folder within folder complexity of bookmarks.