I'm not quite sure what you mean by using dolphins...but they are great ones to be able to get advice, support and ideally even votes from. Many do run (or help run) various communities, initiative or just all around be helpful. However behind every account, minnow or whale, is a person, which is who we're really connecting with (versus their wallet.)

I have to give the disclaimer here that it's up to each individual to decide how to spend or invest their money. But with that said...generally for those of us looking to be here on Steemit for the longer haul, there is value in building up Steem Power (whether from posting rewards or investing) since this increases your influence here with your votes giving more and you getting more from curation rewards. However when purely viewing it as a monetary investment..the end question here is do you think the price of Steem will go up and to some slight degree how much could you make from your own votes/curation.

Personally, I powered up everything I earned on here for my first 3 months...then started to diversify a bit. I'm never comfortable having 'all my eggs in one basket.'