A get-rich-quick scheme is a plan to acquire high rates of return for a small investment. The term "get rich quick" has been used to describe shady investments since at least the early 1900s.Most schemes promise that participants can obtain this high rate of return with little risk, and with little skill, effort, or time. Get rich quick schemes often assert that wealth can be obtained by working at home. Legal and quasi-legal get-rich-quick schemes are frequently advertised on infomercials and in magazines and newspapers. Illegal schemes or scams are often advertised through spam or cold calling. Some forms of advertising for these schemes market books or compact discs about getting rich quick rather than asking participants to invest directly in a concrete scheme.It is clearly possible to get rich quickly if one is prepared to accept very high levels of risk — this is the premise of the gambling industry. However, gambling offers the near-certainty of completely losing the original stake over the long term, even if it offers regular wins along the way. Economic theory states that risk-free opportunities for profit are not stable, because they will quickly be exploited by arbitrageurs.