The Work at Home scam has at least 10 variations. For specific examples, you can check the following scams, under the previous menu: Ads/E-mail processing scam, Craft assembly scam, Data entry scam, Envelope staffing scam, List with clients, for sale scam, Make profit now scam, Marketing kit scam, Medical billing service scam, and Typing at home scam.
In a nutshell, you find an ad, which tells you that you could turn your computer into a moneymaking machine (giving you the example of a guy who already quit his 9-5 job. More details in the Mom makes $612/ day scam). The way the scam works is that you are asked for a fee to receive a start-up kit, which you never receive. Instead, you will be billed huge monthly payments, until you opt out.