In fact there is already positive expected value because some third-party bots give away free bounties in the chat, as well as you can catch free Peerbet credits on faucets.

I've been playing with it for a few days and so far every payment has been processed perfectly.

The site does have a "house edge" in the sense that prices escalate faster than profit payouts.

That said, the house edge can be overcome by smart play.  It is essentially a game of "hot potato", not dissimilar to the stock market, where everyone bids up values for profit and eventually someone is left holding the bag.

The bag holders are going to scream "SCAM!" but, of course, that is part of the game.  If you're the last guy at the end of the profit chain and your grenade blows up all you get is the consolation prize