Is money earned from marketing products on a website that offers discounts of questionable authenticity, without knowing the prevailing prices in other markets, considered permissible (halal) or forbidden (haram)?

It is permissible to promote products and earn a commission for guiding people to websites that sell them. This falls under the category of permissible brokerage. It is stipulated that the products must be permissible. There is no obligation to advertise prices, discounts, or disclaim responsibility for them, so as not to arouse suspicion among customers. There is no sin upon a person for a lie that is not discovered.