There is no argument to be had about Trendyol and Hepsiburada — they hold the domestic habit and a Shopify store is not going to take it from them. That settled, the interesting question is the one most Istanbul manufacturers have never worked through properly: the western marketplaces are where a large share of demand for Turkish cotton, leather, rugs and jewellery is already being met, and it is being met by resellers who bought the goods from a supplier a few districts from yours. They are earning the retail margin on your production. Getting onto those shelves is not a strategy on its own, but it is a straightforward correction of who captures the spread.
Two channels do most of the work. Amazon in the US and the European marketplaces, where a listing lives or dies on catalogue structure — parentage, variations, backend search terms, suppression history — long before advertising becomes relevant. And Etsy, which has a deep base of Turkish sellers and suits categories where craft, materials and origin are the purchase reason: rugs, jewellery, leather goods, hand-finished textiles. Etsy rewards a completely different kind of listing from Amazon, and running both from one content set is how brands end up mediocre on each.
The reason this sits alongside your Shopify store rather than replacing it is arithmetic. A marketplace buyer belongs to the platform: you get the order and pay the fee, and the email, the browsing history and the reorder stay on the other side of the wall. For an exporter that is a particularly expensive trade, because you have just spent money introducing yourself to a market where nobody knew your name. So the marketplace runs as discovery, the store runs as the relationship, and the routes back are the ones the platforms genuinely allow — package inserts, registration and warranty offers, brand tools inside the platform. Anyone promising to move Amazon buyers into your Klaviyo list is describing a terms violation.