Ingredient reputation & concentration
Many buyers cite the high 10% niacinamide concentration and 'famous ingredient brand' status as the reason for purchase, often calling it surprisingly cheap for the potency offered.
Word-of-mouth / online reviews
Numerous reviewers say they bought it after seeing reviews online, from friends, or from social media (TikTok/Instagram) hype about The Ordinary.
Repeat purchase / stocking up
A large share of reviews are repurchases (2nd, 3rd, 5th bottle), often bought in bulk or during sales to stock up because it is a routine staple.
Price / sale promotions
Many mention buying during Olive Young Big Sale, Black Friday, or coupon promotions, citing affordability as a key driver.
Gift purchases
Several reviewers bought it for sisters, daughters, or friends, suggesting gifting occasions tied to its recognizable brand and low cost.