In this book, we propose a marketplace model which is based on personality, reputation and reinforcement learning algorithms for buying and selling agents. We use two personality traits for seller agents: stingy and conscientiousness. In this marketplace, sellers with low score of stingy earn more benefits in comparison with high stingy sellers. Also, conscientious seller agents gain more reputation relative to conscienceless seller agents. In addition, we use three personality traits for buyer agents: stingy, openness and agreeableness