You need to register at Filestar for two main reasons.
First, you need to have an account in order to get your first free conversion credits stored somewhere. Your account will also help you keep track of current credit status and make it easy to stock up on new ones when you run out.
Secondly, we always strive to give you the best experience with Filestar. And we aspire to help you explore how to take your desktop productivity further. To do so we are happy to occasionally send you emails with tailor-made content or software updates. But don't worry, we won't bother you unless we think you will really benefit from it.