Salary
Average Salary: $44,380
Expected Lifetime Earnings: $1,852,776
Let's face it, sketch artists: nine out of ten times, software can do your job better (or at least more accurately) than you can. No offense—your consummate V's are super-impressive—but that 1.5-micron pixel camera phone with the ƒ/2.2 aperture is pretty good too. And it's just a phone. So, what does this mean for you? Fighting tooth and nail for a paycheck, usually.
Drumming up work can take a lot of effort, and even the most consistent and salaried "sketch" jobs out there might require you to creatively claw your way in. But if you're sure you want to turn this talent as a job-job instead of a side-job, then let's run the numbers, shall we?
First off, this profession is so tiny that the government's labor bureau won't even track it separately. If you're doing sketch work, you're considered a "fine artist" (at least according to census data), which puts you at about $44,380 a year on average (source). But—man, there's always a "but," isn't there? —that number is pretty skewed by sketch artists getting lumped in with the likes of sculptors (who are probably pulling the numbers down) and illustrators (who are probably pulling the numbers up).
At the end of the day, freelancers are masters of their own destiny, so their income is fairly dependent on them. But if you have to be a freelancer, a sketch artist freelancer isn't too bad a choice. There might not be an incredible amount of demand, but there aren't a whole lot of people who can draw as well as you, either.