This is fantastic and a bit illegal as you say. There are many companies online today that offer easy ways to earn money online. These are scam companies that will trick people into investing in some sort of get rich scheme and in the end close up shop and walk away.
One such business or scam that comes to mind quickly is the email scam. They ask people to invest $25 to get access to this program. They claim that you can make $400 to $500 a day reading emails. In the end, the program will have you advertise an affiliate link online to attract other clients. They claim that all the money you earn from using this method will generate your profits and income. You are basically selling this scam to another person who will pay you for the information and access to the site. The site will give them the exact same information that they've given you.
There are other online scams where you need to get a downline of people under you who are willing to invest large sums of money in a fast and easy way to make money online. Part of their investment is returned to you in the form of a commission. Your downline is actually the only thing that is generating your income. In the end, the company runs out of money or closes up shop and doesn't pay anyone.
It isn't hard to find all the information you need about online scams and how they work. You can create a site and promote this business online. If people like what you're selling they will invest in your program.