What is 'commodification'? Explain with examples.

Commodification:

1. Commodification occurs when things that were earlier not traded in the market
   become commodities. For instance, labour or skills become things that can be bought and sold. 
2. According to Marx and other critics of capitalism, the process of commodification has negative social effects. For example: commodification of labour.
3. In earlier times, human beings themselves were bought and sold as slaves, but today it is considered immoral to treat people as commodities.
4. Traditionally, marriages were arranged by families, but now there are professional marriage bureaus and websites that help people to find brides and grooms for a fee.