That's a perfectly reasonable relationship between you and an online entity: you understand the nature of the agreement, and you are constantly made aware of the company's actions as a result of your feeding of information to them (e.g., the suggestions you get from Amazon become more accurate as you browse, purchase, and rate products). It's an equitable arrangement.

It's the base assumption on the part of the companies that people tend to forget: "If you are using our service, you are costing us money, and we have to find a way to make that money back." Selling the information you give them is the first thing they sell, not the second, third, or last.

I was severely irritated earlier this year when I applied for a business license. It took a week to get the paper license in the mail. It took two days for business printing services, credit card services, and other bullshit to start sending me junkmail to "Intersection Thereof Software."

It's all about education.