The answer to your question really depends on what your goals are. If you want to maximize your results, you should likely add Internet play to your playing time. If there's a specific income level you want to reach, can do so playing exclusively live, and are happy with what you are doing...that's a judgment call.

Personally, I think that a mix of B&M and online play is the best way to become a well-rounded player. As noted above, you get to play more hands online, which means more experience, while live play teaches you more about people.