TechCrunch thinks that monetizing a url shortening service is near impossible HERE. This is likely because everyone has their head stuck in the idea that the primary value of a url shortner is it's pithiness. In reality, the value of a url shortner is in it's verboseness.

TechCrunch: "How any URL shortener is supposed to make money is still unclear." 

1. If you know what percentage of any given website's traffic comes through bit.ly (easy), bit.ly knows how much traffic that website gets (more accurately than comscore).

2. If you know when any bit.ly url is RTd or reblogged (easy), and the CTR of each generation (easy), you can create ROI visualization like http://bit.ly/RTviz without spidering twitter.com. 

3. Offering market reach or ROI visualization based on each source's readership (for blogs) and follower count (for Twitter), time delay till reblog / RT, and source vintage gives bit.ly positioning you can stick a price tag on. Bit.ly becomes an ROI forecaster and sheds url shortner haircut. Again: http://bit.ly/RTviz

4. While all url shortners' value proposition is making urls shorter. Bit.ly must treat this as a given, then brand itself as THE WAY to know how much traffic your marketing is producing in real-time. And how much traffic your competitor gets...

5. ...and why. Premium accounts tell you when your competitors' traffic spikes and the related (PR, meme, blog) event.

In short, bit.ly becomes the new FedEx tracking number (and tells you when your ex-wife gets a thank-you card from your best friend)

- in reality, this is just the frost coming off of the tip of the iceberg