If you haven't heard of Gilt, it's a site kind of like Hautelook that has lots of short lived but great deals (they have way faster shipping than Hautelook, but other than that they're pretty much the same). Right now one of their deals is a yearly Birchbox subscription plus a $25 credit (a $135 dollar value) for $79.20. That's an amazing deal, especially considering that reviewing all of your products will get you 600 points, which is equal to $60 in the Birchbox shop, so at the end of the yearly subscription you will have paid $79.20 for 60 samples and $85 in credit in the Birchbox shop.
If you don't have a Gilt account, you can sign up here. If you already have an account you can use the link here. Use the code WELCOME20 to get it for $79.20 (otherwise it's $99). If you have ebates you can also get 2% cash back by going through them.
Also, don't forget to add the Mystery Sample Pack to your cart before you check out at Birchbox.com. Even though you've got the voucher, it'll still be free!