Abstract: The inventive method consists in marking sold articles with codes and storing them in a server database. Questions and answers are formed and transmitted to user devices. A random code is produced and compared with a user code. The number (N) of questions is determined according to an expression N=S?M+k, wherein S is the total number of symbols in the sequence of the random code, M is a number of coincided symbols in the sequence of random and user code, k is a whole number. The operations of transmitting questions from the server and receiving correct answers from the user device are repeated, the number of transmitted questions and received correct answers being limited according to said mathematical expression. The played user codes are stored in the server database in order to prevent the participation thereof in following draws.