STEEM represent the amount of crypto currency STEEM an account holds, which cannot be directly exchanged for services within Steemit.
You want to be concerned about SteemPower. Steem Power increases your influence together with your Reputation. STEEM holdings are dead currency and very volatile in value.
One way to achieve SP is to dedicate 100% of your postings' earnings to SP. Oncee you have built that up, you can put value into STEEM, but it is better to put it into SteemDollars... There are many good articles on Steemit.
ch @globocop
thanks