If you could give one piece of business advice (not art related) to artist who are within reach of making webcomics as a full time job, what would it be?
Make a plan. I remember sitting down and writing out a chart before I was doing this full time that said “if I make X selling one shirt and Y from advertising off of Z pageviews and doing a convention typically costs A but nets me B then I need to sell C t-shirts, get up to D pageviews and go to E conventions a month/year in order to do this full time.”
It really is a numbers game. If you have a 1000 readers and make $100 a month (these are imaginary numbers), then you can roughly estimate that you need 30 times the readers to make 30 times the income. About 1-2% of your total audience will spend money directly on the things you offer for sale. Just make that 1-2% as large as possible while still maintaining your creative integrity.