This can really be a solution to the "ICO Problem." First mining and the rest did fair distribution, then an attempt at "airdrop theory" by BitShares community (Protoshares!) couldn't hold their ground to flood of massive ICOs, and now ICOs are fading again because of higher regulatory awareness and insane attention competition for any "utility" token, which has brought the airdrop idea back again, and the full circle is a return to "Proof of X" where X (mining) is replaced by "Brain/Participation."