Green Man Gaming offers a voucher good for 25% off most game downloads when you fill out a short form and verify your PlayFire-linked Steam ID. (Not a PlayFire member? It's free to join.) It beats our April mention of 20% off and is the first such voucher we've seen with PlayFire-linked IDs from GMG this year. Some titles may be excluded from this discount. It may take up to 48 hours for the voucher to arrive.
Almost anyone can do this increasingly lucrative gig and work as few -- or as many hours -- as desired.