I can't believe this didn't get any responses. You've brought up some great questions and obviously come from the proper background to be asking them.

I'm definitely not the best person to answer them. However, I agree with your point about human nature never changing, so we should be anticipating similar issues to those found in previous marketplaces.

@kingofdew here on steemit is a digital marketing guy and has been thinking a lot about steemit too. I'm going to send him this article. He may have some better insights.

Here are my #hottakes on your two main questions:

How do you avoid the social media trap to use the value of the token as a metric for the ROI of your community activities?

I'm not sure if I understand exactly what you're asking, but for me personally, I think the token model for steemit changes all the incentive structures compared to typical social media. If you want to get value out of steemit, you literally have to invest both your time and money (converting to SP is really the only way to see returns).

So everyone here literally owns a piece of the network. The actual dollar value of the token is not so important because we all understand that if we support the network in whatever way we can, it will grow and thus the value of the token will grow. I'm not sure that's necessarily a trap as you put it. It's incentivized me to contribute constructively and think more about what I post than with any other site. That may not be true for everyone, but they will leave unless they find a way to provide value.

How do you involve the large brands with massive budgets that want to participate in your community, not as individuals but in a yet-to-be-defined variant of advertising and sponsorship?

Can you expand on this? What types of partnerships are you thinking about? I could see companies setting up their own accounts and using the "Promote" feature, but they would have to buy STEEM to participate. I'm not even sure the "large corporate partnership" model is one that steemit would even be interested in.

I could be way off though. It sounds like you are much more of an insider than I am.

Thanks for the post and welcome to steemit.