It greatly varies on your area and the type of games available near you. Generally, I'd say online has the much larger potential for making (and losing) money, because you can play many more
hands per hour compared to live poker. You can multiply the number of hands per hour even more if you multi-table online.
Live poker is only more profitable if you are playing in some large game and especially if you have a huge skill edge. If playing a high stakes game against some fish, then of course, you're set up to win big in the long-term. Live poker has more fish, so the right environment, live is very profitable.
I'd say online is still better overall because of how much faster pace the games are, but the right live situation might be more profitable too.