Cultural traditions affect ear piercing just as much as they do circumcision. In Latin countries, especially, girls are expected to have pierced ears, and it is odd not to. I know that in Spain it is traditionally done very early, usually before the child is a month old.
My two cents, I'm from Guatemala, my grandmother had my mom's ears pierced when she was born by the pediatrician. My great-uncle did mine same day I was born, at the hospital, he was a plastic surgeon (btw, they are perfectly placed in the center!). DH got beautiful baby-earrings for both our kids when they were born and the pediatrician pierced their ears at the hospital. DD5's were done the same day she was born; DD2's were done the next day.
It is true, girls are expected to have pierced ears, it is VERY odd not to. I'm glad mine were already pierced by the time I noticed earrings! I don't remember the pain, I think I would hold a grudge over my mom has she allowed me to grow up to suffer and REMEMBER the pain! And it is a cultural issue; I don't see it as a mutilation of the body. To each its own. I won't change anybody's mind, they won't change mine. I think the younger, the better. Ridiculous is very subjective in this case.
To the OP, if you decide to do it, go with gold earrings, at least 10K or 14K that are screwed in the back. Or look for baby earrings. They now sell them with the applicator and the pediatrician said it's really easy and fast to do it. DH got these at jewelry.
The reason behind the gold earrings is that it does prevent infections. When the ears have first been pierced you need to roll the earring and clean it but nothing special, soap and abundant water. When it's healed, if they are gold earrings, you can practically forget about them. I check once in a while my kids' earrings, that the little ball behind the ear is properly screwed, you don't want those that can be pulled free, earrings can get lost or god forbid, swallowed!
ETA: It doesn't matter what age they are, gold earrings is the best anyways to prevent infections. After it's healed, anything goes.
Karla