What is the Proof of Importance (PoI) consensus protocol?

Proof of Importance (PoI) is a protocol that first appeared in NEM (XEM). The selection of miners is carried out based on criteria in the “harvesting” process. Nodes receive important points based on transactions made in the last 30 days, network activity, and the number of locked coins. The higher the overall score, the more likely it is that a node will be selected to validate a block. Unlike the Proof of Stake protocol, a high stake alone is not a guarantee of node selection.