We need to relearn the dark arts of customer service and relationship management. MMO developers know this well; they know how important the forums are, how fans can serve as ambassadors for the game, how what gets said on the forum can raise warning flags early when updates cause problems, how sometimes some of your best ideas can come from your players. Yes, it's true that this kind of information is anecdotal, while your metrics are hard data; that players sometimes don't really know what they want; that players often misidentify a problem (e.g., they say something is "too hard" when really it's too boring); and that quite often you can't do as they wish, because market conditions don't permit it. Of course you keep analyzing your metrics, too.
In the F2P space, by contrast, customer service has been treated as a cost sink, something to be ignored or minimized; many games make it actively hard to find anyone to help when you have a problem. Even when there is a customer service function in the organization, it often is isolated from live teams, with only a trickle of information back from CS to the developers -- and almost never any information from the dev team to players in advance of updates. This is no way to foster a community.
Customer service is not a cost sink; customer service is an opportunity to retain players you might otherwise lose -- and given how much money you spend acquiring players, retaining them is valuable. A customer in hand is worth two in the bush.
The F2P market has been dinged on the fact that most games rely on whales, a small proportion of the audience who spends disproportionately. This raises no ethical issues if your whales are princes from Saudi Arabia or tech-boom millionaires; it is an issue if someone living in a trailer park is spending $5000 they can't afford.
Why not be super-ethical?
The third time within a month that someone makes a real money purchase, pop a dialog saying, "We appreciate your business, and are very glad you want to spend more on our game. But you've already spend $XXX this month. Are you sure you want to spend another $XX?"
Likely with a checkbox saying "I'm fabulously wealthy, don't bother me with this again."
Yep, you'll likely make less money. But you'll build good will. And maybe you'll sleep better at night.
In a retail environment, transactions are simple. If you wish to play Call of Duty, you must pay to purchase it -- but the revenues of its publisher are capped at the standard retail price.
F2P is different. You can use psychological techniques and ethically dubious tricks to slide bills out of your customers' wallets -- or you can get them to want to pay you. And either way, your per-customer revenues are capped only by their willingness to pay.
Isn't it better if they are truly willing to pay?
Why would someone want to pay you?
That is ethical F2P game design; that's what will ensure that your players stick around; that's the smart way to approach a mature market; and that's what will make your game last, potentially forever.
There's a genre called 4X: that stands for "explore, expand, exploit, and exterminate." Too often, we concentrate on "exploit and exterminate." Let's focus more on "explore and expand."