Promotions and coupons are site-aware. Site-awareness can be part of the condition or the offer. For example:
Site-aware condition: A customer who buys $100 worth of merchandise on a given site receives free shipping.
Site-aware offer: A customer who buys $100 worth of merchandise from one site receives a 15% discount on a related site.
Coupons can include site constraints that control which sites the coupons can be claimed on. Coupon site constraints do not affect where the associated promotions are valid.
