Everyone on the server benefits from this. Your monthly support gives the whole community:

• 2x 1.30x Community XP Boost (2 hours each, every player gets the bonus)
• 1 hour Community Professions Boost (all professions, every player)
• 1 Legendary Augment Reroll gifted to every player

For you: the VIP rank while subscribed, and a shout-out thanking you (or stay anonymous with /cosmetic supporter anonymous on).

The boosts go to your inbox Boosts tab, so you pick when the whole server gets them.