ET (thirty minutes after launch exactly) and I got a reply at 3:01p.m. I entered the key and it claims my 'Rockstar Activation Code already in use'. Then the launcher prompted me for my key, again. The RSC account took it and I downloaded the launcher from the RSC website since it added GTA V to my RSC account game library. I activated my Steam key on the Rockstar Social Club website in my RSC account.