Who would have ever thought that you could base an entire business on Twitter, but as Peter's prodigious post  pointed out (don't you just love alliteration), anything is possible in the world of social media.  I don't want to throw water on that notion, but I do want to caution that there is a dark side to Twitter that you should be aware of if you're going to do business on it.  For one thing, it can quickly become a viral nightmare of negative press if you don't nip it in the bud.  Two examples:

Last December Ford's guru of social media, Scott Monty, (I'll bet you didn't know Ford had a social media guru) noticed that there was a flood of angry tweets about Ford supposedly trying to shut down a "fan" web site.  Scott immediately tweeted his followers (and he has a lot of them) to let them know that he would look into the matter.  His detective work uncovered the allegation that this site was marketing counterfeit goods with Ford's logo on them.  By the end of the day, Ford's lawyers had gotten the site to stop promoting the goods and Scott was able to tweet the happy news to his followers.  That's a pretty fast resolution to a problem that could have gotten really ugly. 

Here's another example from Michael Stelzner at one of my favorite sites Marketingprofs.com.  Seems that an employee at New York PR agency Ketchum forgot that everything you tweet can be found on the Web.  The employee was delivering a presentation to a bunch of people at FedEx headquarters in Memphis when he tweeted the following: "True confession, but I'm in one of those towns where I scratch my head and say, 'I would die if I had to live here!'"  Oops!  A FedEx employee caught the tweet and forwarded it to the company's executives.  Needless to say, the Ketchum employee was publicly embarrassed as was his firm.  In effect, the FedEx execs' response said that they were paying the Ketchum way too much money to be insulted by an employee whose presentation didn't give them anything of value anyway.

Bottom line: if you're going to do business (or anything else for that matter) on Twitter, keep in mind that your spontaneous comments and those very personal thoughts you convey to your followers can take on a life of their own and live forever in the digital world coming back to bite you time and time again.