One of the main advantage is the lower shipping cost or it could be zero cost to them.  If the ECAs happen to be within their vacinity, they could arrange for own pick-up.
Other advantages:
1)   Shorter shipping period
2)   Local ECAs mean no exchange rate involve.  If parcel were to come from USA to South East      
      Asian countries for example, cost to import is definitely very high, higher foreign exchange
     (especially now) and higher import duties/sales tax could be applicable too (some countries may
     have to pay GST instead of sales tax).
3)  You can visit your local ECAs to check on their physical products, if they have a physical store
     before confirming your order.
4)  You may bump into an opportunity to market your own product(s) by collaborating with your
     local ECAs if you don't have your own physical store.  Getting to know your local ECAs
     personally, to gain each other's trust may lead to a bigger sales for both parties. 
5)  Easier for you to perform your transfer of buying.
In summary, you get to know your local ECAs better, enhanced your networking, broader your chances to market your own products, save on your shipping cost, faster delivery and by collaborating, you are bringing and helping each other to success.
                                            
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                    One of the main advantage is the lower shipping cost or it could be zero cost to them.  If the ECAs happen to be within their vacinity, they could arrange for own pick-up.
Other advantages:
1)   Shorter shipping period
2)   Local ECAs mean no exchange rate involve.  If parcel were to come from USA to South East      
      Asian countries for example, cost to import is definitely very high, higher foreign exchange
     (especially now) and higher import duties/sales
...
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