You might want to revise your original comment, then. In your first comment you clearly wrote, "In oher words:illegal," but now write, "red flag."
If the customer base exists, and the promoter can rely on word of mouth for advertising, why is it a red-flag to not want to pay anyone for advertising?
Also, why is it a red flag to accept cash, which 100% of attendees can produce instead of relying upon other payment methods which have been shown to make less money for the promoter?
Reflect on it for a moment. In this exact case, people purchasing tickets into a concert, where there is a tremendous amount of business, why pay a third party for every credit card swipe? You get the exact same number of customers if you only accept cash. In many demographics, you actually get more customers from cash-only.
Sure, some promoters and business owners will evade taxes, but people do that anyway for all sorts of businesses. In this case, accepting cash only is not an indicator of attempting to evade taxes.
Because any manager knows that handling that much cash comes with risks. Someone standing at club door taking cash, sans cash register, is dangerous. Either money goes "missing" or someone gets robbed.
That has absolutely nothing to do with your comment that people who accept cash are engaging in illegal activity.
In an all cash business, the truth is you make money hand over fist. You can't count it fast enough, even with your door person skimming - which you already expect to happen. Besides, you don't have your door people stand around all night with loads of cash in their pockets.
If the customer base exists, and the promoter can rely on word of mouth for advertising, why is it a red-flag to not want to pay anyone for advertising?
Also, why is it a red flag to accept cash, which 100% of attendees can produce instead of relying upon other payment methods which have been shown to make less money for the promoter?