Registration, necessary or just annoying

About registration. It can be one what we could study... If you want to use something light and easy tool you dont want to register and receive advertisements to your email. That is the marketing point is this study. To get something you need to give someting else. In these cases your name and your email address. And after that you may get spam. But sending adverticements is one way to earn money. Even you get only half cent per sended mail but if you have thousands of addresses...