I just wanted to point out, that in the world i have been building (stories for kindle) Humans are more often then not the slaves of other races. However, they take slaves themselves. The Empire race is my own creation, they are about American civil war era in terms of tech, black powder guns, metal war ships and electricity. They take slaves at every turn. They have no magical talent so they have started "breeding farms" where they try to cultivate the magic gene. Breeding humans and crossing them with other races.
Humans on the other hand are general fantasy type. Swords, magic and castles. I think they are the most wide spread race still though. Dwarves on the other hand unlike most fantasies are doing very well, they had their "almost extinct" moment and have since brought they population back up to happy levels.
Anyway i could go on for days talking about it. Glad to see other people have noticed these things too.