100s of tabs: what is there?

Those of you who keep hundreds of tabs open: I'm curious how and why you use them. I'd hoard tabs in the past, but in a sad incident a browser (Firefox) restart caused the loss of all my 10s of open tabs that was accumulated over weeks long research about a topic, I decided to never trust tabs again. Now I'm making use of my bookmars toolbar, Org mode and Instapaper for most of the stuff having many tabs open was the method before. So, for me, tabs were for keeping stuff handy during research, read-it-later lists, and temporary bookmarks. What are the use cases for you?