"I was against the idea when we did it at Turbine, and it won’t happen on my watch here at Trion. Lifetime memberships are a great deal for consumers that plan to spend the next few years playing the game, and a financial disaster for subscription-only companies that have to continue paying for new feature development, salaries, server costs, marketing, etc. Ultimately, it’s a bad deal for the consumer in the long-term."
Typically the lifetime offers only ran for a certain period of time, mainly as a way to extract a large sum of money from those who may well end up losing interest and abandoning the MMO after a month or so. Some subscription-only MMOs have since switched to free-to-play, but lifetime users still need to pay for items. This is often mitigated by granting those few with a fixed income of in-game currency.
Rift from Trion Worlds launched back in March 2011 and by January this year it has earned $100 million in revenue.