This difference in turn affects platform design and operation. The seller sends the product directly to the buyer via express delivery or postal parcel, as part of an ecosystem that includes e-commerce platforms, e-payment providers and delivery services (Box 1). This model presents challenges for regulators, particularly customs authorities, in handling the growing number of high-frequency, low-value items traded across borders. Transactions levels are often higher, customers may have more specific expectations and be more demanding, and the process may involve a number of people in the decision-making.