All these buzz about tracking clicks began with Bing, but goes well beyond that Search Engine.
Read this article, it talks about clicks and other telemetries (remote measurement and reporting of information). There are a lot of examples of applications where you have been tracked, knowingly or not.
You could see it as: you give something, and you’re given something in return. I’m not saying you will be always happy with what they did with your information … 🙂 but it’s on the majority’s benefit.
What do you think, where do you put the limit in data privacy? Would you give willingly your habits in order to improve the ‘usability’, friendliness of applications?