In a bout of what I consider astounding honesty and transparency, Dorothy Gambrell -- creator of Cat & Girl -- has just posted her income breakdown (reproduced below) for the first quarter of 2010. Not only how much she made, but where that money came from! (It's listed on her site as if she's done this before, but this is the first I've seen of it.)
A few things worth noting. The money she earns from the sale of original art and commissions is a little under 10% of her total earnings for the quarter; extra freelance work also seems to be right around 10%. Donations account for 7% of her overall earnings. The vast majority of her income (somewhere around 70-75%) is from the sale of replenishible items relating to her comic -- shirts, buttons, prints, etc.
I would certainly consider Gambrell one of the more successful webcomic creators out there. She's been doing Cat & Girl for over a decade, and has built up a loyal following. From everything I've seen, she's doing everything right.
Now, I don't know how cyclical her income is, but it's certainly variable from month to month. I also don't know the full extent of her financial situation -- what her debts might be, what other sources of income might be available for her household, how much she has in savings, etc. It certainly seems as if she's making a living primarily through Cat & Girl.
Personally, I wouldn't be comfortable living with that variability. That's why this blog is a part-time gig for me and I go into an office for nine hours a day, five days a week. But that's me. That's based on my priorities and I wouldn't necessarily recommend that to anyone else; it's what works for me.
But, given how little information is out there regarding what a webcomic creator might expect to earn, I think it's quite laudable that Gambrell's willing to share this and well worth passing around. Take a look at what she's doing. That she's making a comic barely even registers on that graph. She's spending time working on t-shirt designs and stickers and all sorts of stuff ON TOP OF making a thrice-weekly webcomic.
Those donations buttons are nice, but they don't pay the bills. For that matter, neither does making a comic. No, what's paying the bills is all the work that goes into your business AFTER you've created your comic. That graph up there? That's your business model. Study it carefully.