I can tell you the difference between me being a user and not being a user is this exact feature.

I can buy stocks on my own in different quantities to make my own “ETF” (granted not at fractional share prices)

But if I could bundle it and make a small commission for it, you’d have my business for the rest of my life

Also, what an awesome incentive that would be for me to share your product around with others who would invest in it! I’d literally be getting paid to do it!