What goods through trade make byzantine successful?

After silk worms were smuggled into Constantinople (from China, where their export was prohibited) in the 7th century, the city began producing valuable silks which fetched very high prices in the West. These included luxury silks woven with gold thread. Italian (especially Genoese and Venetian) & other merchants came to Constantinople for the products of Anatolia: cotton, rice, wheat, saffron, wax, wool, hemp, raisins, alum, valonia, slaves; cotton textiles & precious silks from Blikesir. Imports included valuable woolen cloth (saquirlat), tin & lead.