Case Study: Underclub achieves 10x growth and boosted conversions with Mailchimp postcards and Facebook ads

How a multichannel strategy is bringing conversion success and growth to Underclub's subscription‑based business

Underclub, an Austin-based subscription lingerie service founded by Katie Fritts, needed to scale customer acquisition and grow brand awareness. To reach new and lapsed customers, Underclub turned to Mailchimp’s multichannel tools—specifically Mailchimp postcards and Facebook ad campaigns—to create a more personal, targeted outreach.

Using Mailchimp, Underclub segmented engaged-but-not-yet-purchasing contacts and sent targeted postcards with a 30% off promo code, while running a separate Facebook win-back campaign for inactive subscribers. The Mailchimp-driven strategy produced immediate conversions and ongoing responses as mail arrived, contributing to significant growth—Underclub reports roughly 10x growth in the past year.

Underclub

Katie Fritts

Founder