B2B2C marketing is about leveraging the B2C marketing strategy and implementing it on the “customer” level that is facing the “consumer’s”.
The B2C marketing strategy has to drive demand generation from the consumers and in turn, the consumers engage with the customer to complete the sale. The role of the business here is to support the B2B business with B2C as an agency would.
The reason why this strategy is employed is that the B2B businesses have a better reach and command of the B2C captive audience and it would take a long time and longer effort for the business to go direct and build this relationship. Therefore the business approaches the B2B partner that already has this long-standing relationship with its consumers and facilitates the marketing and outreach to them in their brand's voicing.
The benefit to this is that the demand generation activities and strategy are controlled by the business and not the B2B partner and they have the control on how to drive demand generation content to their brand specifically without diluting their equity.