I would go one step further (or two):
Set aside a large amount of steem power to upvote content creators that bring new users with the caveat that the new accounts need to be bought. Whoever brings new users get larger votes.
Condition the content creators to keep their vested steem powered up.
I actually wrote a post about that:
https://steempeak.com/steem/@onthewayout/how-to-create-demand-for-steem-using-social-influencers
I personally don't think you will keep large influencers here with just the upvote model. Their pay changes too much with the fluctuation of the currency and isn't reflected in the popularity of their contributions. Which is why ad revenue needs to be part of it.
That's why in the post I mentioned that ad revenue would be part of the model.
I was just going off of what you mentioned above, if it includes revenue sharing I am all for it!