But what should you do if you’re already in the guild? Steal things, duh. Get double the items from crafting nodes in Hew’s Bane, more rewards from Heists, double the whiskers from killing bosses in the Maw of Lorkhaj, and doubled rewards from world bosses and delve bosses in the region. It’s twice the reward for the same amount of effort! Any good thief would be interested, and you’ve got until March 20th to enjoy the spoils.
The Elder Scrolls Online is throwing a one-year anniversary party for the Thieves Guild, it’s doing so discreetly. Everything is very hush-hush. (This is different from celebrating it discretely, in which case the party would be very clearly separate from any other parties taking place, making it a worse idea.) If you still haven’t gotten in to the Thieves Guild content, for example, you can do so with a 25% discount in the Crown Store for the DLC or you can purchase the CE package at a discount as well.
Source: Official Site