Low ROAS After an Olive Young Sale? Funnel Conversion Data Shows Cart-to-Checkout Drives a 5x ROAS Gap

When a campaign’s ROAS comes in low, the number alone doesn’t tell you whether to change creative, add budget or widen targeting. ROAS reports the outcome, not where shoppers dropped off. Buzzvil’s analysis of co-op ads during Olive Young’s September sale — Korea’s largest health and beauty retail event — shows that the answer lies in funnel conversion rates by stage.

Funnel conversion benchmarks from the September sale

Shoppers move from ad impression → click → engagement → Olive Young app visit → add to cart → purchase. Median conversion rates for purchase-focused campaigns looked like this:

• Impression → click: about one in four people who saw the ad clicked
• Click → engagement → app visit: most clickers engaged (quizzes, reviews) and continued into the app
• App visit → add to cart: roughly 12 in 1,000
• Cart → checkout: about one in five

Up to the app visit, brands performed similarly. The gap opened inside the app, where shoppers browse, compare prices and weigh promotions.

Where the ROAS gap is widest

Splitting brands into high and low converters at each stage and comparing ROAS:

• Brands with high cart-to-checkout rates had more than 5x the ROAS of low converters
• The app-visit-to-cart stage showed a 3.5x gap
• Click and engagement stages showed little ROAS difference

That doesn’t make upper-funnel stages unimportant. It means that when ROAS disappoints, in-app behavior is the first place to look.

Category averages are a weak benchmark

Median cart-to-checkout rates ranged from the 9% range in hair care to the 28% range in makeup. Within skincare alone, rates spanned from low single digits to the 30s. Because price points, audiences and promotions differ, the best benchmark is your own previous campaign — compared side by side, with differences in budget, offers and assortment noted.

Case study: lower checkout rate, 1.7x more purchases

One skincare brand changed three things between its June and September sales: it ran an audience-building campaign in July, switched on purchase-focused campaigns in August before the sale began, and expanded creative from one product image to four formats, including quiz, review and coupon-alert ads.

• App-visit-to-cart rate rose from 1.6% to 2.8%
• Ad spend rose 1.3x while sales rose 1.9x, for a September ROAS of 612%
• Cart-to-checkout rate fell from 32.5% to 24.5%
• Yet add-to-carts grew 2.2x, so actual purchases rose 1.7x

Looking only at percentages, checkout seems worse; looking only at counts, you miss the rate decline. And since three changes happened at once, no single one can claim the credit.

Takeaways for your next sale

1. Find the stage where shoppers drop off. Too few add-to-carts and too many abandoned carts call for different fixes.
2. Read rates and counts together. A falling rate can hide rising volume, and vice versa.
3. Study in-app and on-site behavior. For your own store, free tools like Microsoft Clarity show exactly where checkout hesitation happens.

For teams that want to systematize recurring campaign reporting, Buzzvil’s business team also shared how it runs 32 automations without developers.