Eeehhh, I gotta disagree with that. Maybe it requires less character design effort (unless you're doing a gijinka comic; then it requires about 800x more) but in terms of writing and drawing a good fancomic will take just as much effort as an original work.
I mean, unless you just plan to redraw the source material scene by scene and not bring in any new ideas whatsoever...
...I do agree on that, though. My fancomics are the only ones with a decently-sized fanbase. ^^; If you're good (and in some cases, even if you suck), people will find you all on their own.
Fanworks are born in passion, y'know? Every once in a while you run into some source material that just brings something out in you that you didn't know you had...
^This is a page from one of my fancomics...and for some reason, none of my originals ever look nearly as nice. ^^; But whenever I sit down to work on this, I just get so inspired, and I really love the whole process. Even if I can't make any money on it, even if it takes time away from stuff I CAN make money on...I don't want to stop.