A lot of people want to shrug off Twitter as something that's going to go as fast as it came (anyone remember MySpace?), but even if it doesn't stick around forever, it looks like it's going to earn some money while it's here.
It's estimated that twitter will earn around $150 million dollars in revenue in 2011 from advertising, up a whole lot from the $45 million they earned in 2010.
So you may want to think Twitter isn't doing much, but they're definitely doing what they can to hold their weight and bring in the dough.
Source: Twitter Ad Revenues to Soar This Year, eMarketer.com