Business is business! SFI's business. If you want success, earnings and believe that the SFI then it needs to invest. If you SFI party, then the party and that you're going to do something and make money, the question is!
So it depends on how you understand - what is SFI.
SFI is a business-investment is necessary!
SFI is fun - you do not have to invest!
Select and do so!