Re: people, this is a troll (m)
Courtney seems to have caught on in UK just as it was sort of falling out of fashion here.
And while Brittany started out as a fairly upscale name, it did rather quickly acquire a "trailer trash" vibe, which may or may not have had something to do with Britney Spears. But Courtney has, at least to me, carried a definite upper-class feel to it; all kinds of people are named Courtney, mind you, just as all types are named Brittany, but Courtney started out as a yuppie sort of name and while it gained a wider appeal, it never sank to the level that Brittany did.
I like both names though, and definitely like them more than Poppy.