Word-of-mouth and online reviews
Many buyers state they purchased after reading numerous positive reviews or recommendations from friends, influencers, or content creators before even trying the product.
Brand trust / line loyalty
Existing users of other numbuzin No.9 products (serum, toner, mask) purchased the eye cream expecting similar quality and results.
Anti-aging ingredient reputation
Retinol, NAD+, and peptides were cited by name as reasons for purchase, particularly among users over 30-40 seeking preventative or corrective anti-aging care.
Repurchase/loyalty
A large number of reviewers mention repurchasing 2nd through 8th times, indicating high repeat-purchase behavior once trust is established.
Gifting
Several reviewers bought the product as a gift for mothers or mothers-in-law with mature skin, citing its reputation for eye-area care.