Sub-steem
A sub-steem is like a subgroup on reddit. This allows special communities to have their own private space on the platform where whales from the other groups don't have voting power by default and therefore can't dominate. For example we don't want English speakers dominating trending posts on the russian sub-steem. This is especially useful for other languages and NSFW content so as to not bother the mainstream users. Sub-steems will prevent steemit from splintering out into alternative sites/blockchains like golos.io have done.
The golden opportunity
To sell stake for STEEM in the newly created sub-steem's is the golden opportunity. This will create a demand for the STEEM token and qualify people who want to be part of any new sub-steem. They have to burn some STEEM to get voting power. The ICO profits from each sub-steem creation can be burned to reduce the total supply of STEEM. Trading in and out of any sub-steem can happen on the internal exchange and create a possibility for additional profits in the form of trading fees.
Let a 1000 sub-steems bloom. Cha-ching!
If STEEM doesn't do this, some other project will ...
An experiment within an experiment. I love it! (picture of Michael Jackson eating popcorn in movie theater)
Sub-steems will happen according to this quote from @ned "Sub-steems are a definite future!" . Hopefully they will also get their own tokens so as to profit through ICOs. Read more here: https://steemit.com/steemit/@inertia/substeem
Thank you!