Re: Steemit how can this thing be workable long term?

Potential issues that I came across today

1) Someone pointed out the fact that steemit has no fees. My question was, ok, then how does it prevent spam?

Quote

https://steemit.com/steemit/@steemship/the-missing-link-has-steemit-revolutionized-micropayments-or-made-them-obsolete#@alexgr/re-steemship-the-missing-link-has-steemit-revolutionized-micropayments-or-made-them-obsolete-20160719t214207846z

"1.) Problem: Fees. Solution: Steem has no transaction fee."

Question: Isn't that an attack vector where someone can just bloat the blockchain - in the order of terabytes? How is that avoided here?

2) 10% interest on Steem Dollars

Quote

https://steemit.com/steem/@craig-grant/steem-dollars-is-designed-to-be-a-comfort-zone-for-those-who-need-usd-10-interest-is-toilet-paper-money#@alexgr/re-craig-grant-steem-dollars-is-designed-to-be-a-comfort-zone-for-those-who-need-usd-10-interest-is-toilet-paper-money-20160719t184633720z

I wasn't aware of the 10% interest on steem dollars, but it would definitely have consequences in terms of real-life economics if it builds up in terms of people having them parked to get interest.

If steem dollar = dollar, then that would make the steem platform something that would attract a lot of external investment to acquire steem dollars appreciating at 10% per year.

So say a fund comes along and buys 10mn steem dollars in order to make them 11mn steem dollars. That's -1mn dollars for the ecosystem in the end of the year. Is this sustainable? I mean banks get your deposits, give you 2% interest and then loan you with 5% - so they have a business model where they have income. Here there's no income except inflation. So perhaps that would create a lot of pressure in steem price as a lot of steem would be needed to support all the steem dollars interest.

I think 10% interest on SD is net-negative for the system unless I'm overlooking something (it's possible that I do).