in fact, time ago I heard of a guy (he was like...60 years at the time) that made a series of novels for kids, and he only had money for publish it or pay an artist, so he decided art the stuff by himself in PAINT. when people asked him why he just said that it was easy to use and he didnt have idea about other software. And the arts he did were really nice!
Link
keirajo
Never underestimate the power of MSPaint! XD