gimmick — a trick or device intended to attract attention, publicity, or business

a carnival game operator enthusiastically demonstrates an oversized spinning wheel covered in huge fake prizes. He spins the colorful wheel dramatically while pointing to enormous stuffed animals hanging above his booth. When the wheel stops, he quickly hands a tiny plastic toy to the disappointed customer instead of the big prize shown. The customer looks confused while holding the small worthless item, realizing the display was just for show. Other potential customers nearby start walking away after seeing the obvious deception. a trick or device intended to attract attention, publicity, or business