Won't you receive the same POS if you kept it yourself?
No, I think it's 1%/year roughly for Proof of Stake.
Obviously this is -EV for me long term as i'd be holding the same amount of money "invested" in a transparent account as a guarantee (e.g. I could just invest this money myself without giving 1% interest), but I think it's more an an idea to create a use for some PPC / reason to hold them than create profit if this makes sense?