FBA is in many ways a brilliant service, as can be seen by its enormous popularity. Benefits include:
Amazon does most of the work including customer service and delivery and you have the benefit of selling to Amazon’s enormous customer base.
Pay as you go fulfilment service with no contract or minimum fees
Most fulfilment houses will make merchants sign up to a long term contract and will need to pay for a certain amount of storage space. They may also need to pay for incoming deliveries. Amazon does not require any of this
FBA offers have preferential buy box treatment
Amazon gives Prime eligible order which are fulfilled by Amazon a better change of getting the buy box, increase sales potential
FBA offers are Prime eligible
FBA order are eligible for Prime, Amazon wildly popular subscription service.
FBA orders can be delivered throughout the EU from the same inventory
FBA inventory in the EU can be delivered as Prime eligible offers from the same inventory pool.
FBA is available in most Amazon countries
FBA is available in most of the countries which Amazon operates in. The system is the same in each country and so this can be a convenient way to expand internationally.