Hey now, don't forget that the more users we get, the more exponentially faster we will grow.
Look at Myspace, for example. According to Wikipedia, it managed to get 20 million users its first year in 2003. 2004 brought 40 million, 2005 brought 80 million, and in 2006 Myspace hit 100 million users. As of last week, Myspace has just hit 200 million users. What does that say about the site? The user count doubles almost yearly! Myspace was first bought out in early-mid 2005 when there were roughly 50-60 million users for close to $600 million.
Now I know we are nowhere close to being as big as Myspace, but Im just applying the same equation to a smaller scale. The more users we get, the faster we will keep growing, and 100k users is definitely one of the first large accomplishments when it comes to user counts.