OneCoin was a $4 billion Ponzi scheme from 2014 to 2016, founded by Ruja Ignatova, a Bulgarian entrepreneur. The coins could not be traded and had no value since they could not be used to purchase goods or services, making it nothing more than a scam. That said, the core business of OneCoin was selling course materials, although most of these material were reportedly plagiarized.

The company promoted its course material business model through a complex network of recruiters and affiliates who were paid commissions to bring new buyers into the scheme. This setup, where recruiters and affiliates are paid recruiting commissions, is a multi-level marketing (MLM) strategy that was widely used by OneCoin.

Sadly, OneCoin's founder, Ruja Ignatova, has been missing since 2017 and its co-founder, Sebastian Greenwood, is currently incarcerated in the United States. Not surprisingly, the scheme has left victims in its wake, leaving thousands of investors with huge financial losses.

In conclusion, OneCoin was an elaborate Ponzi scheme that relied on the sales of plagiarized course material and, more importantly, a complex network of recruiters and affiliates who were paid recruiting commissions to convince new investors to get involved. The scheme is now gone, but it has left thousands of investors with heavy financial losses, a reminder of the danger of fraudulent schemes like OneCoin.