Is there a community around this like /r/churning? Preferably sorted by reward to effort ratio (e.g., $20 giftcard for a 5 min referral signup with personalcap

Is there a community around this like /r/churning? Preferably sorted by reward to effort ratio (e.g., $20 giftcard for a 5 min referral signup with personalcapital.com that you can just cancel after was pretty good).