After ICO scams in 2017, the new kind of scams are emerging in Proof-of-stake coins space, specially MasterNodes way is getting bumped up the sentiments of people become overnight rich out of air. They don't know how badly they are caught themselves.
In simple words, Proof-of-stake in any form whether Delegation PoS or anything else, is good compared burning electricity point of view in PoW coins however there is lot of flaws in designs to fit in for very very long time is yet to be proven under blockchain distributed ledger technology with its safety, security & integrity or consensus.
As of now, any PoS is RISK to invest if it is new and listed in less than 10 exchanges (is must) to trust and safeguard your investment.
The reward will be distributed in a monthly basis to the stakeholders or master node and if that was not having a lot of liquidity and the price of POS or MN coin can't defend its price. It's simple to be dumped when there was no a lot of volumes.