The most profitable online business for you is the one that is the best match for your skillset and which you can expand the most.
It’s possible to make thousands a day from trading foreign currencies, but if you don’t know what you’re doing, you’ll probably lose your money straightaway. Equally, being a personal assistant isn’t hugely profitable in general, but if you have a knack for it and go on to create your own agency, the sky is the limit.