Say I'm business A. I'll offer a portion of my business (say 40%) with the offer that you will reap 40% of my profit. (Assuming one person pays in for that whole value).(edit: I offer this as the income will allow me to expand where as otherwise I'd have to wait longer depending on profit)
At what point does almost anything else you mentioned help the business?
Everything else seems likes gambling, imho, and I still can't wrap my head around why it's allowed.