Early-bird store event

Wiktionary Word definitions in Wiktionary
n. An unusually low sale price, typically offered by a retailer on a limited number of items for a limited time, often on prominent shopping days, such as the day after Thanksgiving in the US.

Wikipedia Word definitions in Wikipedia
A Doorbuster deal in economics is a term which refers to an offer which is handed out early into the business's opening hours, with the intent of attracting large numbers of shoppers into the business. A typical doorbuster deal is an item or selection of ...