Say you're notoriously good at feeling good start-ups, but you don't necessarily have/want to invest money. Now you also have a good network of people that wish to invest in these startups, but they wouldn't have access to such deal or know how to do it.
You can set-up an SPV in which we build-in your carried interest. That way it's a fair deal. You get compensated by your work (due diligence etc..) in taking 20% of the uptake. And your investors have nothing to do but to on-board on Vauban, sign a few papers and make a wire transfer.
The important point is that your investors know what will be the underlying company. This is also useful because trendy startups tend to take minimum tickets of $200k+ which can be hard to stomach for an Angel investor, especially if you want to invest in a lot of deals to get a diversified exposure