Wants for sale

I have a hard time understanding art or at least understanding what good art is. Recently my good friend Amanda introduced me to this site, it is a couple in NYC who are trying to make a living as artists. They draw a painting of something that they want and then sell it for what it's worth, sometimes it is thousands of dollars and sometimes it is free. Here are some examples:

"A Slice Of Pepperoni" $3.00

"An iPhone" $432.42

They also turn New York trash into art.

I hope to one day participate in Christina and Justin's creative way to make money. I think its safe to say that I understand this kind of art :)