Can someone show me a chart showing the issuance of Sia over time?  How many exist now and how many will exist after the initial issue?  And you appear to have a perpetual block reward?  That is smart. 
 
So a motivated miner could conceivably mine for their own permanent storage on the network at any given time? 
 
You've got my attention Sia, and that's not easy to do.  I'll be keeping an eye on you.  (Of course, Vanillacoin caught my eye at one point too so don't get too flattered - I'm secretly an idiot)