I wrote one blog post which was intended to present the case for blogging for fun with the potential that the small rewards could compound over time. I wasn’t intending to encourage people to buy more STEEM on the exchange market and power it up to STEEM POWER. I think you put it best, that safest is to invest the STEEM POWER you earn from the site. We’ve seen far too many newbies lose money investing on risky altcoins and generally the rule is don’t invest in what you don’t entirely understand.

The math behind the compounding of STEEM POWER (SP) is more complex (than I originally thought when I wrote my prior blog). It depends on the ratio of STEEM to SP in the money supply. When the SP to STEEM ratio is 9, there is no compounding gain. When higher the compounding is a negative variable interest rate and when less than 9 a positive one. The 90% interest rate that I had assumed is probably not realistic.

Steem is complicated system to analyze from an investment perspective. Hopefully some others will write some unbiased blogs which delve into this more.