The massive sum for Jesy Nelson, Leigh-Anne Pinnock, Perrie Edwards and Jade Thirlwall will be a result of several contracts with major brands including beauty firms and clothing manufacturers.
A source told British newspaper The Sun: 'Little Mix are just a marketer's dream.
'They are just the full package.'
X Factor boss Simon Cowell has got high hopes for the band and believes that they're the Spice Girls in the making - and they have been receiving offers for weeks before being crowned winners.
A source added: 'Offers have been coming in for weeks now.
'People in marketing spend their lives looking for suitable role models. Little Mix are the full package. The trick will be knowing what to turn down.'