Boot Boyz Biz does monthly drops (usually the third Thursday at 3PM CT). Everything sells out in a few minutes. There's always a few tees, sweatshirts, and hats, but usually drops will have wild card items like ping pong balls, blankets, chairs, or drinking glasses too. Each item's design is a mash up of ideas and graphics from art/philosophy/pop culture, etc. Every item is accompanied by a graduate level essay detailing where the graphics came from and what they mean. I get such a silly little dopamine rush from their products. If I recognize just a single concept from one of the pieces, it's an instant buy. Aside from looking cool, they've introduced me to a lot of new ideas I might not have known about otherwise. Items are also reasonably priced for being so limited.
