Colonial aka Imperialism normally had the stated aim of making profit. Whatever was the cheapest method of getting goods was normally done. Mass murder was normally avoided as it depleted the labour pool, pushed up prices and increased instabilty which meant paying for more soldiers.

It got so expensive that before New Zealand joined the British Empire the British were trying to figure out how to scale back the number of colonies. Independence was a long way off but it was a solution the Brits were happy with.

Nazi Germany mass murdered its own citizens and those of countries it captured. Not because they offered resistance or because it was profitable. They killed them because of idealogical reasons. The mass murdered had the wrong religion, wrong sexuality, the wrong politics or the wrong handicap.

It wasn't for profit, it wasn't even neccesarily for security and it was done on an industrial scale (something IMDHO which is a Teutonic trait not something from facism otherwise the Italians would have shown better organizational skills).