Starting today, Smashbox is running a promotion for their Illuminating Serum. Normally, the Serum costs $33. Smashbox is offering it for free with any $55 purchase. If you’re planning on replenishing any of your Smashbox products in the near future, you’ll want to take advantage of this offer for sure. Please note that this offer is good for one week only. It ends on January 16!