Carrd

Carrd runs an in-house referral program (not a third-party affiliate program) that pays 30% of Pro plan fees on a referred user's next upgrade or renewal, paid as account credit that is cashable via PayPal. One-time per referred user (referral codes are single-use), 30-day cookie, $25 minimum, payouts on request within about 5 business days. Free and open to all users; paid-search and branded-keyword bidding are prohibited.