If we all are so keen to mass adoption of steem chain, then why to offer such a contest like this. I am not trying to de-mean your effort, rather trying to submit my points.

A registration fee(no matter how small is), be it in cents always perceived as a turn down for newcomers. It is considered as a barrier to entry. You may say that you have the other options also, which is free registration but has a waiting time like 2 weeks which is another turn down. The point is that- if we are so serious about lowering the barrier to entry then why not offer a 1 month free registration window by @blocktrades or Steem-ninja(@oracle-d) to on-board newcomers to steem chain. You may offer this, with a robust verification and introductory post(with some matching code to verify the authenticity of the new users) which can prevent spam & multiple accounts. This way, you can get more natural and organic users to join Steem chain.

Account Registration and transaction through blockchain should be instant and free, if you are keen to on-board.

While we have Steem chain as a great blockchain in which the transaction cost free, but we have a very poor registration process. This is a fact. If we can accept this fact unanimously, we can have a solution.

With this contest, you are trying to reaching out to the influencers or even the regular steem users to make a whisper to their peers in their social circle who have not joined steem chain yet and in return, you are offering a lucrative reward in this contest. So let's take this for granted and have a fair analogy then.

You can save more or on-board more if you offer a 21-day free registration window and I am sure that can yield a better objective for you as the later may bring more natural or organic users.

This contest would have been justified only if you had a specific purpose to invite the celebrity/social influencers from other established community. In general terms, I don't see this contest fulfilling your objective.

Note- I am really sorry if I have, in any way, hurt your sentiment. I have just tried to put forth my apprehension.