Historically, obtaining a key for older versions like uTorrent 3.6 might have been sought after for several reasons:
The search phrase may also indicate an interest in obtaining a cracked version of uTorrent Pro (the paid version). Several third-party sites offer modified versions of uTorrent Pro 3.6.0 that claim to unlock the "professional" features and remove advertisements. These are often described as "破解" (cracked) or "绿色版" (portable/cracked) versions. utorrent 36 key link