They trick legitimate businesses with convincing fake invoices and paperwork, so everything just seems real, and then they set up eBay and Amazon accounts just to compete with the people they've already sold fakes to.
Engañan a negocios legítimos con falsos, pero convincentes documentos y facturas, de modo que todo parece real. Y crean cuentas en eBay y Amazon para competir con aquellos a quienes vendieron los productos.