CurlKit Black Friday Sale in Spring: Save 40% on Everything! Last updated by Hello Subscription on March 17, 2018. Subscription Box Coupons & Deals / CurlKit Coupons Hello Subscription may earn compensation via links in this post. Read the full disclosure Save for Later Notification CurlKit is having a Black Friday in Spring sale! Use coupon code BFS40 to save 40% on everything! Will work on subscriptions if you add something else to your cart, including the multi-month ones in the membership tab.