Brand reputation / repurchase of the line
Many buyers already used SKIN1004's original (non-tone-up) sunscreen or other Centella products and purchased this version because they trust the brand ('go-to' sunscreen, repeat purchases mentioned repeatedly).
Desire for a tone-up/foundation-replacement effect
Reviewers specifically bought it to even skin tone or skip foundation, citing the tint as a key motivator over plain sunscreens.
Ingredient reputation (Centella/iron oxide)
Several buyers mentioned choosing it for calming Centella ingredients or iron oxides for extra protection and redness reduction.
Sample-to-purchase conversion
A number of users tried a sample at Olive Young or through gifting before deciding to buy the full-size product.
Value for money
Multiple reviews call it 'good value' or worth the price relative to performance, especially compared to pricier Western sunscreens.