Well, not necessarily, but we encourage you to do so. Please note the difference between having and not having an iChess account before making your purchase:
• You purchased that course you liked and had no iChess account: you will receive download links with your invoice directly to your email inbox.
• You have an iChess account and made a purchase: you will receive the download links plus streaming capability. Download and streaming links are added directly to your account. Yes! You can stream your courses with iChess apart from being able to download them if so you desire.