They shill your product endlessly. What's the conflict of interest? They market for you, as they have a vested financial reason to do so. I mean it's no more a conflict than anyone else promoting their investment.
The US financial system does not allow or encourage people who "shill" for investments. We in fact have many protections and policies that limit your ability to solicit investment in unregistered securities, which is what virtually all ICOs are/were.
Investments aren't always in money. They can be in a form of vendor lock-in. It eventually results in massive hidden losses nobody warned about, but shilling was above sky.
I mean that the subjects of their "marketing" might come to the conclusion that advocates are primarily interested in attracting more speculators rather than selling a product they genuinely think will help you.