I barely play Demigod but I love getting coupon codes from Stardock for a cheaper Demigod. Shows good customer relations etc. Wish I was on the receiving end (that's what she said!!). Anyhow, here's a 75% off coupon code. I don't know if it can be used more than once:
Refer a Friend!
It's the time for glory, when Demigod players shall band together
and recruit their friends to join them in the battle for true godhood!
Forward this email to a friend and they'll received 75% off their
purchase of Demigod using the coupon code below.
The person who refers the most friends, are destined to win a prize,
as our way of thanking you for referring your friends.
Coupon Code: DGFRIEND-3207488
This offer is valid for a limited time only and can not be used
with any other promotion. Expires: April 8, 2010.
Visit Demigod Website: http://www.demigodthegame.com/
Offer is only valid for Demigod (Digital Download).
The way they word it makes it seem that it can be used more than once.