I know it's been discussed in a couple other threads but since this will be it's own box it deserves it's own thread. From their email (link deleted since it's no longer available):
Special Offer From Vichy + Birchbox
Based on your beauty profile, we think you'd like an introduction to Vichy through an exclusive collection of their complexion-changing products. This limited quantity members-only sponsored offer is in addition to your regular monthly Birchbox. The sponsored box will ship mid-February at no extra charge, filled with four deluxe samples of Vichyâ€™s innovative anti-aging formulations.
Would you love to try Vichy? Click here to let us know*. Quantities are limited and while supplies last. If we don't hear from you it is possible you will receive the sponsored box.
Hereâ€™s to gorgeous skin!