I've done it.

As mentioned, jingles is one. Diversify: learn sound design, audio restoration, VO cleanups, understanding video production and work as part of the team (majoring in audio) - this means not just as a separate process but an integrated team from the beginning.

It's got a lot to do with entrepreneurship. You're selling something that people can download illegally online for free, and those who need it done legally are in a market where people want unrealistic quality at zero cost.
This is why I think people in the music business are one of the best business people around. See Richard Branson or our very own Tony Fernandes