What motivates companies like starbucks to expand into international markets with little percieved interest in their product?

The fact that companies so powerful and famous are capable of creating a demand where it doesn't exist. Great companies don't sell mere products; they sell experiences, social status, etc. With the right marketing, they can adapt their global brand to the local needs. That is why Starbucks managed to open many stores in China, a country with the tradition of tea drinking.