To me the question between the two is somewhat loaded. Let me explain why:
To participate one needs an account, and an account has a minimum cost
1 acc = 1 Nxt(open acc) + 1 Nxt(register public key) = 2Nxt per account
This is wrong. Why? Because a medium-sized holder (500k NXT) can do this for free in about one day. Just include all these transactions in his own block. No fees.