California law requires retailers who advertise discounts or product specials to have enough products available to meet the expected demand or to provide a substitute product of comparable value at the advertised price.
If only limited quantities of advertised specials are to be made available, or if the advertised product will not be available at all store locations, the retailer must disclose that information in its advertising.
Sometimes consumer demand is greater than a retail advertiser could have reasonably anticipated and the company runs out of the advertised product and cannot substitute a product of comparable value. Although not generally required by state law, some retailers will issue rain checks (promising to provide the goods at the advertised price in the future) in order to preserve good customer relations. However, rain checks are not an adequate substitute for a shortage of the advertised goods.
In one situation, California law says rain checks are required. If a company offers a gift or a prize to get a consumer to come to a sales presentation and, despite the seller's good faith effort to have a sufficient number of gifts or prizes on hand to meet the expected demand the gift or prize is no longer available, the company must either give the consumer a comparable substitute or deliver the promised gift or prize to the consumer's address at no extra charge within a reasonable period of time, but no longer than 80 days from when the consumer attended the sales presentation.