Hey Google When did I ask you to read my Purchase details
kanoki.org
kanoki.org
The thing I don't want is them using my data against me, which is about all they seem to want to do. For example figuring out that I will pay more than other people for that product is using it against me. Figuring out that I have a higher likelihood of a medical condition because of my searches and then reporting that information to insurers would be using it against me.
So yes, use the data to benefit me, and don't use the data to harm me.