I used this promo code on iStockphoto today and received $15 off my $75 purchase. So I only paid $60 on iStockphoto for 50 credits. A pretty good deal if you ask me. If you click the link above I will get a small commission thanks.
Here is the code - Promo Code: stocklayouts
Thanks to Elizaibeth for turning me onto the promo code.