The Secret World is having a double XP weekend, and my housemate-slash-guildie was just diagnosed with a fractured fibula. It's all coming up Milhouse.
The Black Weekend starts on Friday June 14 at 9:00AM EST and ends on Monday June 17.
Every day that you log in during the event, you'll receive a double XP potion that lasts eight hours; access the item store to claim your potion.
While you're in the item store, claim your free Black Boots.
There's one other direct bonus; anytime you earn Black Bullion in-game, you'll get one extra. Black Bullion are traded for high-end gear.
Otherwise, there's a special recruiting bonus; any new players you recruit will score you free membership months (or $15 of credit if you hold a lifetime subscription). Your recruit must be invited anytime from today till the end of the event, and must purchase the client within 30 days.
The Secret World is free to play but you must buy the client once a trial has expired. It is supported by optional subscriptions offering bonus items and free DLC, as well as a micro-transaction store packed with cosmetic items and boosts, and semi-regular paid content updates.