Interesting read I found while perusing Jason’s blog:
Here’s what it does: when the Google toolbar is installed and when the autolink feature is enabled Google will hunt through your requested web page and auto-link content for you, e.g. given an ISBN number it might autolink you to Amazon.com. It’s a neat idea and somthing Microsoft tried with Smart Tags a couple of years ago and I’m sure it has all kinds of revenue opportunties for Google: instead of buying ad words in search engines you can buy ad words on any web site!
From a technology perspective: cool idea! From a consumer perspective it sends up all kinds of red flags. What’s next replacing existing URLs? Honestly, how hard would it be? …and most consumers would be none the wiser. Google could sell your every click.