Out of the Box Sampler isn't exactly a subscription box, because you decide each month if you want to order based on the theme and vendors. However, each month, boxes are made available in the first few days of the month (the theme is revealed the month before and spoilers go out to get you ready). These sell out fast - and you will quickly see why!
This is also an amazing opportunity for crafters. For information on donating to a future box, you can visit this page and get more information. They even tell you themes for the year, shipping dates, etc. so you can plan. It appears they're pretty open to anything, too, as long as it's related to the theme and it's a great way to get your name in front of lots of people as a crafter.
January's sampler was themed "Baby It's Cold Outside" and you can see the giant list of vendors on the paper below.