77 of Korea's 100 best-sellers are sold in a pack, not alone.

Korea's best-seller chart is a bundling chart. On Olive Young Korea's top-100 list for 2026-W31, 77 of the 100 slots carry a set, multipack, plus-offer or multi-type marker in the product name; only 23 read as a single item at a single size. What tops Korea's chart isn't just which products win — it's how they're packaged to win.

How much of the chart is sold in a pack?

More than three-quarters of it. Of the 100 top-selling slots, 77 carry at least one merchandising marker in the title — "Set," "Double," "+1," "1+1," a piece count like "10ea," or "7 types." Only 23 are a plain single item at one size, and those tend to be single-purpose products where a bundle makes little sense: CAREPLUS's spot patches at #8, a JUNGSAEMMOOL cushion refill at #9, AESTURA's Ato Barrier 365 cream at #12. Everywhere else, the default unit that charts in Korea is a package, not a bottle.

What kinds of packs are they?

Four patterns account for almost all of it. Sets, bundles, doubles and duos are the most common, appearing in 59 slots; plus-offers — "+1," "1+1," a free extra — appear in 30; multipacks that state a piece count like "100 pads" or "10 sheets" appear in 25; and multi-type packs that bundle several variants ("7 types," "4 options") appear in 15. These overlap — one product can be a "10ea Set (+1ea)" at once, which is why the four counts sum to more than 77 — but the direction is one-way: the winning offer on Korea's shelf is almost always more units, not a lower unit price stated on the chart.

Can one product hold several slots at once?

Yes, and that is where bundling and concentration meet. Torriden's Dive In low-molecular hyaluronic-acid line holds 6 of the 100 slots by itself (ranks 10, 28, 44, 51, 60 and 87), charting as different sizes, sets and variants of the same serum. MEDIHEAL's Essential Mask packs take 3 slots (ranks 1, 4 and 20) and numbuzin's masks take another 3. So the same packaging logic that fills the chart with sets also lets a single hero product occupy the board several times over — one reason "100 products" overstates how many distinct formulas Korea's top 100 really contains.

What this does and doesn't tell you.

It reads packaging, not receipts. These markers are parsed from the product titles on Olive Young Korea's public best-seller list for 2026-W31 — the country's largest health-and-beauty retailer — so a "set" means the listing is sold as a set, not that a discount was applied or that a shopper saved money; a plus-offer is a stated bonus, not a measured price cut. One retailer is not the whole Korean market, and a title without a marker can still be a de facto bundle we didn't catch, which would push the 77 higher, not lower. What the number does show is a merchandising habit strong enough to shape the chart itself: in Korea, the thing that sells best is usually the thing sold in bulk. That habit is what we'll track week to week — whether the pack share holds, and whether the same hero products keep multiplying across the board.