In my opinion a important aspect is "promoted posts". Right now, to promote a post, you need to "burn" Steem. But what if people could "burn" RC to promote their posts (just like the RC burn to create free accounts), that would be an incentive to power up!! And that would create a competition for vote selling and buying.

Also, maybe give a bit more of visibility for promoted posts, like, show one promoted post of that tag every 10 posts.

Those two measures would for sure make Steem interesting for holders...