By default, contracts apply to all sites. If you have multiple sites and need to restrict the contract to only some sites, use the Sites tab to specify where the contract will be active.

Readysell suggests using specific retails for specific products only, not for very large groups of customers or products.

Sales orders and quotes, deliberately hold the price that was in place at the time the order was created, even if the contract prices change after.

​The reason is that if order and quote prices change when contracts change, then customers might get a different price for the sale than the price originally quoted or emailed to them.