It seems that standing around in demigod generates some gold over time even when I'm just standing back buying items at the store.

Does anyone know what determines how fast I get gold?

Obviously, killing opposing demigods gives me a big gold boost, but what about killing grunts, do they give me gold?

If killing grunts does give me gold do I need to get the last hit, or just be nearby? Do my teammates across the map share the gold when I kill grunts?

If killing grunts doesn't give me gold, is there anything else that I should be doing to get gold, or it is just killing demigods?

Thanks a lot.