Who is the most popular vocaloid?

Of the four 'official' Vocaloids. I think Miku Hatsune is the most popular. I didn't go around the world in a plane counting Vocaloid fans, and I didn't look this up on google, or Bing, or whatever. But, Miku has the Most songs. I might not be the most reliable soarce, so... I would look up songs by different Vocaloids on YouTube and compare the views and likes.

Hope this helps! ^-^

-Kerushii-chan