The goalpost has shifted from 4 months to 4.5 months

[Rolder50]

A.) If you don't make the game more accessible to new players, and all you have are people gradually filtering out, then the game ends for all of us (you included) sooner rather than later. Investing in ways to attract and retain new players is essential to the long-term lifeblood and enjoyment of an MMO.

And if you don't make the game enjoyable for the existing players, then they will leave faster then you can get new players. Also, word of mouth from existing players having a good time is a fantastic advertisement tool.