Of course Neopets isn't an SNS. But, that's the point. It's minimalistic, there's just a taste of it.
It's like the Gateway Drug, sure it isn't that bad and the effects don't completely blow your mind. Why would they? It'd scare the little darlings away that will be giving you money the rest of their lives... Gotta start small.
I think it's interesting that we've gone from villifying people who met over the internet (circa 1980-1998) and now it's become not only acceptable, but common place. It just shows hwo mainstream the internet and virtual interaction has become.
That being said, it wouldn't surprise me if within the next few decades we became a society completely reliant on the virtual domains for interaction. It sounds far fetched, but a decade ago I couldn't have imagined Rupert Murdoch investing in a company like MySpace.