On the surface, Steem sounds like a ponzi. Interest here, you get money there, everything gets balanced out in this incredibly complex way. And if there were no reason for people to keep steempower, I'd say it would be a ponzi. But steempower is a good for the end user, that depletes over time if unused. I'd say it probably will deplete over time even if it is used. But it has an irreplaceable value, and that will cause it to grow immensely, and mechanisms in place to provide stability.
Steem's Elusive Value
What is this mysterious value in steem? Well, it's right there in the name. People with large amounts of steem get unwavering attention, and yes men. When I post this, I doubt I'll get more than a couple upvotes. I might go viral, but the chance is pretty small. But if a whale posted this - they'd be certain to get tens, or even hundreds of upvotes! Why?
Steem's Bandwagon Effect
Curators are rewarded based on the dollar value of a post at the end of 12 hours. More so, the sooner they upvote it (after 30 minutes). So minnows trying to get more steempower are bound to jump on the bandwagon if they see a young post starting to gain steem. And what's the easiest way to start that process? Be a whale and upvote your own post! Just by buying a bit of steempower, you're practically guaranteed an audience for whatever cause you want to talk about! That's a great service.
Steem's Yes-Men
Also, commentors will love to comment on a whale's post because that gives them a chance to get one of the really valuable upvotes. And they're almost certain to agree with the whale, again to increase chances of an upvote. They might not agree entirely, but rarely would they dismiss it with disdain.
Steem's Long Term Outlook
As long as whales enjoy their experience, they won't power down their steempower. The only risk of steem failing is if many whales decide to power down, and even then it won't fail quickly. But I'm confident that whales will be addicted to the attention. Many powerful men surround themselves with yes men anyway. Now, for the first time, they can do it on the internet, and it isn't even that expensive. This is a market too good to pass up.
I predict a huge amount of growth as wealthy people who would enjoy an audience discover steemit. They'll power up and never power down. Probably, advertisers will jump on the bandwagon too. A cheap, consistent advertising platform? That gives dividends to active accounts? The market potential is even bigger than normal whales!
And everyday users will enjoy steem too. For them, it's just like reddit, but they get rewards too. Seriously, steem is a win for everybody. Thanks devs!