When describing whatever it is your promoting, share your experience! If you can throw in some data or graphs to go along with it, even better. Back when I was more actively writing about eHow, I promoted an ebook that I read which helped quadruple my earnings per article. I created a graph that showed how much I earned before I read the book versus how much I earned after. To this date, that ebook has been one of the most successful affiliate promotions I’ve done on this blog.
This is the basic mistake they've made: they've fallen prey to the belief that money and meaning are two totally separate things. They've chosen to make their money from something that feels completely meaningless to them (some business they care so little about, they just can't wait to get away from it and minimize their involvement as much as possible), which they hope will buy them the freedom to do something they actually care about.
You are also free to choose a fund that is based on any index that you want. For example, there are index funds set up for just about every market sector there is — energy, precious metals, banking, emerging markets — you name it. All you have to do is decide that you want to participate, then contribute money and sit back and relax. Your stock portfolio will then be on automatic pilot.
Creating passive income is the key to retiring, especially retiring early. If you want to retire early with the stock market you will have to save a huge amount of money, because that money has to last so long and retirement calculators depend on you using your investment to fund your life. With passive income you will have income coming in as long as you own the investment, without every eating away at the principle invested. Creating passive income may take more work than investing in the stock market, but I think it is well worth the extra effort!