One of my clients built a pretty good online business for natural health and beauty products.He used mainly Google Adwords to do it. You can also use Yahoo's network. After one and half years he is grossing $7,000 per month. He nets about $3,000 a month after paying Google and his suppliers.I think that is a good job. You can also take ads on good websites.In other words you must pay for it one way or another. Check out Wahm Search Engine
http://www.wahmsearchengine.com