The problem with this is if we open publicly and have such instant payment, you know some people would make accounts up to minimum requirements, posting bad quality posts, then bot spamming hundreds of posts with randomly generated after joining campaign, right before a CRON, to then immediately withdraw.
What if make it open to public but the payment is still sent manually weekly right after the campaign manager check their participants posts quality if eligible for payment or should be denied? If a user only made spammy post then it will be a free advertising for the site, if anyone dont want free advertising then they will be forced to make high quality posts