Translating not only listing copy but the listing images into each target marketplace's local language, executed via Seller Central's little-known 'country specific images' link on the image-upload screen — assigning a distinct, localized image set per marketplace instead of reusing one English set everywhere.
One seller identified this as her main lever for lifting conversion and cutting PPC cost across non-English EU marketplaces, after discovering that 90% of her Swedish search-term report was in Swedish — meaning an English-only image set was serving a market that searches and reads in-language. Complements Amazon Global Marketplace Expansion via Single Sign-In (getting into a marketplace in the first place) and Helium 10 Magnet (Seed Keyword Expansion) / Helium 10 Cerebro, whose translation columns let a manager who doesn't speak the local language still act on the resulting foreign-language keyword lists.