Warren Buffet has a CNBC interview recently where he says Bitcoin is "dollars on both ends" and compared bitcoins to checks and money orders, suggesting that there isn't a lot of money in it. That's not necessarily true.
If you've mined coins, you haven't put money in. If you work for bitcoin (and there are small opportunities to do so), you're not putting dollars in. Also if you buy goods and services directly with bitcoin, dollars don't come into the picture.
The actual BTC economy is only a small part of the bitcoin world but it does exist. It is real. It is also growing.