Earlier quoted context omitted.
I have over 150k songs scrobbled to Last.FM and have been a member since 2005. I actually can think of very few other services that I would care as much as if my Last.FM was compromised/deleted.
Ditto. 196k since '05 here. The ability to see how my musical taste synced with the ebb and flow of my life is something I really cherish.
You're scrobbling songs during your whole work day, right? I disable it at work, since I don't pay much attention and end up with lots of plays I don't care much about.
(edit: my average is really 10 songs/day!).