well..there are many ways to get money incoming for a website business.
Customer paid is one, of course.
Advertisements is the other, and when the website is good/big market then much more money would come in through that.
That 's the idea i get from those other websites.
It 's just a matter of balancing/ choice.
But why not getting more money through advertisements or silly marketing questionaires ?
The "trouble" with paying a vip arrangement is that it easily becomes too addictive (300 simultaneous games..yeaaah) because once paid for it , you will want to use it to the max (hey ? a ranking system..let's see how far I can get within this year).
And that can screw up yr (social) life considerably.
Of course for those who have the time (professional jobless

) and want to excell in this game should pay extra (technically they require the webmaster to buy more/bigger servers).
But maybe it should go stepswise ( 0-10 free, 11-50 10 USd, 51-100 15usd 101-unlim 20 USD and some extras like factorization of score points in wins with resp. 1.0 1.1 1.4 2.0 ).
It 's not a demand, or critique..only a wish. A thought.
Have a good evening.
