Legal analysis: 1. When the parties buy jewelry, the jeweler provides a coupon of 2000 yuan. 2. The jeweler is suspected of committing a crime by offering 2000 coupons. 3. It constitutes an illegal act.

Legal basis: People's Republic of China (PRC) Commodity Circulation Law.

Article 39 The State shall formulate a unified system for the collection, processing, inquiry and publication of commodity circulation credit information, establish an intergovernmental credit information sharing system and a public service platform for commodity circulation credit information, and provide inquiry services to the society. The state encourages third-party professional credit evaluation institutions to provide credit services.

Fortieth promoters shall establish a credit evaluation system and a credit disclosure system for trading places, and prohibit on-site operators from fabricating credit evaluations by themselves or through others. At the request of government departments, sponsors should provide relevant credit information.