From work i do online, it is not passive thought. Doing some consulting here and there.
My fist operation so far is kindy greyzone, selling license keys. It works in certain countries. Made it a week ago, already 2 sales. I am marketing it trough some low profile channels, its doesnt take a lot of time to do the marketing, 2-5 new ads a day.
Would like to start a second operation while the other one is running semi-passive. Just dont know yet where to start, maybe a christmas offer of some sort since the holidays is near. I have unlimited hosting for websites, the maintenace is paid for the next coming 6 months. The only cost will be registering domain names, but they are cheap thougt.