Overview: PoPP is a consensus mechanism that both identifies users and distributes new currency into the system. In PoPP, an algorithm leverages identification software in order to link users to payments. Once identity is validated, users send fiat money and receive cryptocurrency in exchange. PoPP incentivizes people to leave fiat for crypto, and users receive a percentage of cryptocurrency as that incentive. 

Strengths: PoPP is an effective method of ‘bootstrapping’ users to enter and interact with the system. By receiving cryptocurrency for every transaction (processing payments), users are rewarded for using the system. Furthermore, PoPP coins claim to have instant transactions without any fees. 

Criticisms: Criticisms of PoPP coins stem from identification software required to use the system, which many say goes against the entire ideology of a cryptocurrency. It’s unclear that PoPP uses a blockchain at all, as there is no distinct mining, staking, or validating process that has been illustrated. PoPP coins are entirely centralized.

List of Coins: MetalPay (MTL)