I guess as you say, mostly oil, dope, people. I wouldn't put the house on any mainstream source for land size occupied by the IS, since that varies according to political need, but most seem to agree it's the wealthiest of all jihad groups. I would guess it also exports jihad, though Europe's a bit slow on the uptake so might take a while longer to sink in while Trump bombs the ideology into oblivion.
To be fair, there is an argument that as infidel western leaders that know nothing about Islam have declared the IS to be unIslamic, the one thing it could never export is jihad. Gimme time, I need to work on this one.