So for anyone who hasn't seen the updated of my Hatsune Miku concert, there I actually posted a video where these youtube guys that hosted became new fans of her just by randomly including their video in one of the "kids react" videos.
This also happened with me and my friend in some way. We were listening to that concert and for some reason, quite liked it. My friend was impressed and I downloaded full HD concert from internet, just to see it... well fully. XD
Some songs are catchy, but especially how they combined all these costumes at concerts and dances and.. It is very impressive and good!
So bottom line, who hasn't heard of Hatsune Miku, go and see her songs. I was listening to her even before I joined theO but only remixed versions of some famous songs and was even then impressed how it was different.
Still I prefer Miku, but there are other vocaloids as well, especially the famous twins (you know on which I am talking about), they are pretty good and Luka is coming to the scene too. They might as well get a fully prepared concert one day.^^ (They actually have even now appeared as guest singers)