If I may offer a late response, here' s how PoP works in as close to ELI5-format as possible:
It starts with the miners.
Similar to a federated consensus algorithm, PoP has a "members only" club of mining nodes called the "Node Registry" who's members are allowed to create blocks. However the gatekeeper to this club is no human or organization, but code.
Similar to Proof of Stake algorithm, each of these nodes holds some amount of ZBC tokens which are used to insure their trustworthiness. However on ZooBC the amount at stake is likely to be wildly disparate between nodes & one's coinbase reward is not proportional to it.
The relationship between the two heretofore unrelated consensus algorithms:
1) Roughly once a day, there is an opportunity for n amount of new nodes to be admitted into the Node Registry.
2) The winning nodes are chosen by simple auction; whichever nodes have staked the most tokens this round. Stake is set by nothing more complicated than supply & demand.
From this moment forward, both their reward and their continued existence in the Node Registry is determined solely by their positive participation in the maintenance of the network. Nothing else.
Their Participation Score gradually fills up to 100% with every block created or propagated, and is penalized when they fail to do so or to produce a valid receipt of having done so.
And with every block created, the coinbase rewards are psudo-randomly distributed. Every node in the registry has ~(1*P)/n (where P is Participation Score between 0 and 1, and n is the sum total score of the entire Node Registry) chance of being the recipient.
I.E. if there's 1000 nodes, each with a perfect Participation Score, everyone has a 0.1% chance to win each block's reward.
This is **an element of fairness & integrity** not present in most other blockchains. For example in Bitcoin or Ethereum, all a mining node has to do is create blocks. It's taken on good faith that node operators are also contributing to the blockchain's health by propagating blocks and transactions. Good faith which has been completely abused in PoW's race to the cheapest, with the work now left to altruistic validating nodes (which should not have to exist for a chain to be secure).
Unlike PoW and PoS, **the chain can't be attacked quickly** because even if the attacker makes the n highest bids every single day they can only acquire n new nodes a day. And they can't really purchase existing nodes because you can't change the ZBC address a Registered Node is owned by... at best the attacker would share the private key with the original owner (and anyone else they sold to), who could at any moment cut and run with the stake.
And in the one fell sourcecode tweak we've also cut off the rich-get-richer head of the centralization hydra: One cannot become a networking-threatening whale simply by buying up a huge amount of nodes & reinvesting their compounding interest, because **there is no compounding interest**.
The rich still get richer, but not so rich that they become an existential threat.