STEP 1: Create or log in to an Alienware Arena account.
STEP 2: Claim your Sniper: Ghost Warrior 1 key.
STEP 3: Make sure you have the Steam desktop client installed or you can download it here.
STEP 4: Create or log in to your Steam account and click the "Games" menu.
STEP 5: Choose "Activate a Product" on Steam. Follow the onscreen instructions to complete the process.
STEP 6: The 90% can be found in the coupon section, and will apply to your purchase on check out.