1) It's very unlikely for an ear piercing to get infected/ cause major damage.
2) Ear piercings (especially in the lobe) eventually heal over time. If you find out it's a mistake, it'll be gone before you know it.
(If you're female)-3) Earrings draw attention to the face, so people don't look at other places.
(If you're male/parents don't care about people oogling your chest)-3) It allows you to express yourself without being over the top, letting your 'inner self' flourish
(If you're male)-4) Earrings often reflect certain aspects of a male persona, whether it means they're feminine or 'gangsta'. Allowing you to express yourself to females (Or males) without spending precious educational time flirting.
4) Earrings are cheap (Offer to pay for it)
5) You'll get your ears pierced when you're 18 anyways.
There, five.