Twitter's user base has grown from 1.6 million a year ago to an astounding 32.1 million, and yet the company still has just 45 employees. The Wall Street Journal (subscription required) took at look at the microblogging sensation's challenges, namely "hiring, to keeping its service up and running, to finding meaningful revenue," in an article that wonders how the service will deal with "sudden stratospheric growth."

Even in this dismal economy, one of Twitter's biggest issues is hiring new staff to outpace its growth while working out a viable business model.

"For the entire [three-year] history of the company, most of the resources have gone to managing growth and that is still the case," Twitter CEO Evan Williams told the Journal, adding that it could have around 90 employees by the end of 2009. "If it weren't growing nearly as fast, we would be building a lot more things."

Williams admits that he's in unchartered territory. "I've started a bunch of companies but never run one of this size," he told the Journal.

Twitter executives have been interviewing candidates with experience for potential business development ideas but have turned down most of them. For all intents and purposes, Twitter is sticking to its long-held game plan: grow and make Twitter the best it can be.