What is the ruling on a prize offered by a company to whoever finds a specific number in their purchases?

The method used by the company to promote its products, which relies on purchasing a product that the buyer does not need in exchange for a number that may or may not be found, is feared to be a form of gambling (qimar) and speculation (maysir). It is considered a deception of people and a waste of money. It is permissible to buy these products if the number is present in all products, making the prize a pure gift. Similarly, it is permissible if a person buys the product without intending to get the prize, and then finds it.