Can you use the Vanilla Mastercard to buy stuff online?

I was just wondering because i want to buy one so i can buy stuff on yesasia.com but i could never figure out if you could use it for online shopping since the website for the vanilla mastercard is useless (i think) so if anyone could please tell me if you can use it for online shopping? and does a $100 dollar card only cost $100 dollars or are there any other fees? (sorry this is my first time trying to buy one) thanks