Quote from zorro:
This isn't about paying for a service. This is about the fairness and integrity of the markets.
Ever play Blackjack? Having live data is just like a standard game of blackjack. You pay to play and you see each card at the same time as everyone else. But lets say you can play this new game. Now, whenever the dealer deals you get to see the card before everyone else. What's more, go ahead and have a bet before the card hits the table.
Casinos try try to fight card counters because it costs them money. Exchanges make money from inviting and providing the tools for "card counters" at the cost of the majority of market participants.
From the NY Times article: