It is possible to make money online without spending any. You can go to clickbank and become an affiliate for free. Sign-up, find a good product to market for a company, and start advertising using completely free methods. When you don't have money to advertise, you have to wait longer usually for the money to start rolling in. Whenever you start an internet business, you have more of one and less of the other. If you have no money, then you need to put in time.
Marketing for free does work, but does require more time. If you can wait, you can make some money by being an affiliate. If you need any help or some free stuff about marketing or being an affiliate, send me a message and I can hook you up with some free stuff.
Google "secretcashblast" and click on the result that says Make Money in 24 Hours. It's a good blog with some good info. Also, you can google "nickstraffictricks." He is a good internet marketer, and his site has TONS of free stuff and guides and techniques that should help you a lot. Good Luck.