^ I think many would probably disagree, but I believe the biggest difference between SNSD & KARA is the company. SNSD coming from SM meant that at the start they already had such a big chance to succeed, same goes for Wonder Girls with JYPE finally having a girl group. Yes DSP is one of the main bigwig companies but I don't think it was as big as the SM rep... But KARA did have the tail ends of Fin KL's success I guess.
Secondly, KARA aren't as perfectly beautiful as SNSD, from an unbiased perspective. I love SNSD but I won't deny the fact that probably the majority of their fame is purely because of how they look (sad considering the talent in the group as well, it gets lost imo)... KARA have had to deserve their success... having sexy butts REALLY helped, but that still took two years to be noticed!
BTW, anniversary in 2 weeks, I should think of something to do.