내돈내산 /nae-don-nae-san/
Bought with my own money (not sponsored)
Short for '내 돈 내고 내가 산' — 'I bought it with my own money.' Used by creators and reviewers to signal the review is honest and unsponsored.
Examples
내돈내산 솔직 후기입니다
This is an honest review — bought with my own money, not sponsored
광고 아님, 내돈내산이에요
Not an ad, I paid for this myself