Philip Bogle:

"Suppose you have compiled a list of the 20 best sources of reviews on the web, and you want to leverage Google’s full text index to search these [through its API]. This isn’t possible to do, because Google allows only a single "site:" specified in a query.
Suppose you have structured data about people and their home pages, and you want to build a search joins your data with Google’s unstructured index. Sorry, not possible.
[...]
Second, the business model failings: when you use the Google API to get search results, you strip out all the value of the adwords model– the Google API doesn’t even expose advertisements, or have a meaningful revenue sharing model. This makes the Google API ideal for building toys that get 1000 hits a day, but bad for building meaningful commercial services."

I know I’m in a rut about this, but Google is making so much money with its core AdWords product that it’s not really taking its many other initiatives seriously from a business perspective (the most outrageous example of criminal neglect being Froogle). I’m betting on a monetization frenzy two quarters after the first signs of a slowdown (which I realize is going to take at least a year or two to happen).
The Starbucks of the Internet.