There's really only two MILLION miler levels that even matter to me; 1 million and 4 million. Maybe 3 million, but definitely not 2 million.

With any kind of serious business travel, 1 million is fairly easy to achieve for many, and I was helped along by the Continental and United merger, as those two airlines were my main ones at the time.
Now sitting at 1.7 mio miles, and likely achieving 2 million at one point in the future, but couldn't really care less about that.
3 million won't happen for me...