The Proof of Importance (PoI) algorithm in NEM allows users with a minimum of 10,000 XEM vested in the system to generate new blocks in the blockchain and earn rewards, including a share of transaction fees. PoI also enables users to make transactions with other networks while receiving rewards. Your PoI score is determined by evaluating your total transaction amount, and a higher score leads to better rewards. To boost your PoI score, you simply need to engage in more transactions with others.