Final answer:
The duration of the 'Nickel Mug' promotion cannot be determined without additional context about the specific campaign, such as the company, timeframe, and region.
Step-by-step explanation:
Without additional context or information identifying the specific Nickel Mug promotion being referred to, it is not possible to provide a definitive answer to the question. The duration of a promotion such as the Nickel Mug can vary based on the company, location, and historical period in which it occurred. In order to provide an accurate answer, more detailed information on the promotion's provider, timeframe, and region would be required. Promotional campaigns can range from short-term events to multi-year strategies depending on their success, target audience, and marketing goals.