If I had to put those in order:
1. Improved media (better textures, sounds, models, etc.)
2. New features.
3. Bug fixes.
4. Performance (higher FPS).
5. Catching and banning cheaters.
6. Drawing and retaining more new players (improved accessibility, etc).
7. Other.
My reasoning is as follows...
Make the game better...THEN...draw more/new players.
If you create a massive draw campaign right now you will be drawing new players into an old media, old features, buggy, low fps system. The sustainability will be lower than if you did those things to improve the game FIRST...THEN enacted a campaign to draw in new players.