Twitter's Automagical Advertising Approach (What if it goes awry?)

Twitter's ad came out a couple of days ago. It's does a reasonable job of explaining how to put promoted tweets and products work for you. You can promote yourself in two ways: promoted tweets and promoted accounts.  It's pay-for-performance, in case you were wondering (you pay when users interact with your tweet or follow your account).

What caught my attention about Twitter's pitch was that you really don't have to do *anything* extra except pay. No searching for long-tail keywords on Google, no setting up Facebook ads. Nothing. According to the video, Twitter will look for and get your account promoted in front of people who have interests similar to your current followers.Twitter will figure out your most effective and popular tweets and promote them to this new audience as well. No new content is created. Twitter just adds a layer of zero-effort promotion on top of your usual activity.

Like anything that's so simple and easy, there is potential for things to go horribly wrong:

• Promoting tweets to people who are similar your current followers means you run the risk of either amassing a large mass of "clones", having a small initial population of skewed interests determining your follower accumulation trajectory. or both.
• How do you split test a tweet?  How can you measure and improve your advertising effectiveness? All you can do is promote and pray.