Ok, posted as you requested, but just before you get too excited because I used the word "tier" I wasn't meaning network tier (aka masternodes), I was meaning monetary tier. A very different thing.

A secondary monetary tier is a credit supply (albeit on potentially a 1:1 reserve ratio) levered off the base money supply. (Such as was described in the Dash blockchain budget "Proof of Labour" proposal).

(What we trade on exchanges is one such secondary tier. That is a credit tier, backed on a 1:1 reserve ratio by a blockchain deposit).