There has been a lot of reaction to Twitter’s announcement that they have made an official Twitter BlackBerry client.  Of the reaction I found Chris Dixon’s the most logical.  In particular, his prediction for the future:

So what might Twitter’s business model eventually be?  I expect that Twitter search will monetize poorly because most searches on Twitter don’t have purchasing intent.  Twitter’s move into mobile clients and hints about a more engaging website suggest they may be trying to mimic Facebook’s display ad model. (Facebook’s ad growth is being driven largely by companies like Zynga who are in turn monetizing users with social games and virtual goods.  Hence it’s no surprise that a Twitter investor is suggesting that developers create social games instead of “filling holes” with URL shorteners etc.) Facebook’s model depends on owning “eyeballs,” which is entirely contradictory to the pure API model Twitter has promoted thus far.  So if Twitter continues in this direction expect a lot of angst among third-party developers.

This is an old marketing ploy, it’s known as a bait and switch.  The classic example is the advertisement in your paper this morning for a $499 42″ flat screen at a local electronics retailer.  The problem, when you arrive at 11am, the local retailer will have already sold both of the 42″ flat screen TVs he had in stock.  He is happy to see you though, and thrilled you decided to buy a new TV, in fact he’ll show you the rest of his more expensive inventory right now.

Twitter needs to be very careful about this.  As I mentioned in the post on their valuation, they haven’t built something that can’t be copied.  Right now their competitive edge over Facebook’s identical functionality is that their API is so friendly (and consequently there are so many nifty applications built on it).  Destroy that relationship and Facebook will gobble you up like today’s MySpace.