I know we already have Subscription Enablers, but Birchbox has so many different codes, that I feel it deserves it's own thread. If Mods disagree - feel free to move this post into the Subscription Enablers thread.
Here are all codes that I'm aware of.
These are one time codes which are supposed to work only during anniversary month. However, they seem to work during a short window (usually around 3rd week of the month) every month after the anniversary as long as you haven't used them.
20% Off your order codes:
WelcomeOffer20 (for the first order)
These seem to work on and off and usually require $35 minimum.
New subscription codes:
BBJETBLUE10 - 100 points
SUBSCRIBENOW50 - 50 points
BLEND - adds BeatyBlender (and, I believe cleanser) to your box
These usually work only once for each account.