Not in the freemium model. In the freemium model it is easy to get many registered users because you're giving the basic version of the game for free and charging for extras. And if 10% of users pay for some extras at all, you may consider yourself very lucky. Typical paying users share is 2-5%. Another problem is 1 million of those users don't play all the time (we had only 5% of them logged at a time), however it is possible to get most of them active for a short time by organizing special events / competitions for them. Therefore you need to have capacity for handling that 1 million of users for a very short period of time, therefore you need to scale, but you are not going to make money from them constantly.