No, right not premium accounts are not available on agar.io but this would be a great ideea for the monetization of this game but in the same time will ruin it.
There are a lot of guys (like me to be honest) that don’t buy stuffs on games just to be the best. I like to play, to be the best on my own not for 3$ 🙂
If the agar.io developers will introduce premium accounts I guess a lot of people will stop playing it because I’m sure that there will be people who will buy them and will dominate the game, of course, excepting the ones that are playing with cheats 🙂
The single option that I see for agario premium acounts without disturbing the “normal” players, is for an extra life. I mean, you have 1500 points, you have been eaten and on restart you start again from 1500 points. That would be pretty ok for me as non-premium user 🙂