Today, November 29^th, we are celebrating Black Friday ? a date created in the United States in which companies offer products with great discounts, traditionally the Friday that follows Thanksgiving. In view of some problems faced by Brazilians in the past year, such as masked prices and misleading propaganda, the Professor of Rio de Janeiro Law School (FGV DIREITO RIO), Ricardo Morishita, gives tips for those who want to take advantage of the best deals on this date.Morishita advises consumers to ask themselves if they really need the product they intend to buy when they see an attractive offer. No matter how great the discount is, if the product does not have a purpose, the purchase will not bring benefits, he explains. He also advises to conduct price surveys to evaluate whether there is, in fact, a discount.Another tip is to learn about the store's reputation on websites like Procon, Senacon and Sindec. For online shopping, there is also the possibility of returning the product after seven days of its delivery, if the customer regrets the purchase.  In such cases, the store is obliged to return the money.The professor also explains that if the purchase is made and the consumer has a problem, such as a misleading offer, defective merchandise or if he/she does not receive the product, he/she must pursue his/her rights. The first step is to talk to the store. If no solution is offered, the customer must go to Procon or the Small Claims Court.