and you're an expert on this matter because?
Because I spent a few minutes reading through the thread to see how the campaign manager runs it before successfully applying myself a few months back.
And why the unnecessarily not accepting someone? Not sure why my account would not be accepted other than the fact that they werent open for new registrations?
From looking at your posting history I would think you didn't satisfy the campaign manager's requirements for quality of posting, you mostly post one-liners. Also, they are mainly in altcoin threads, as 777Coin is a Bitcoin Casino that's not really targeting the right audience for the advertiser.
You can tell they have open slots by checking the campaign spreadsheet, they remain open because so few applicants meet the required standard.