My baby sister's been wearing thongs for years. And no, she's never worn them so the waistband shows. That's generally a "fashion" statement.

When I asked her, "aren't those things uncomfortable?," her reply gave me pause. She told me, she'd rather wear something that's designed to be a thong, than a regular pair of panties / knickers that's volunteering to be a thong.

And she's right - a decent thong really is more comfortable than a pair of panties that's got the creeps.