Under what condition can a court exercise specific jurisdiction over an online retailer?

A court can exercise specific jurisdiction over an online retailer if the retailer targets customers in the forum state. Specific jurisdiction is established when an entity has established sufficient contacts with the state such that exercising jurisdiction over it would be consistent with traditional notions of fair play and substantial justice. Targeting customers in the forum state signifies purposeful availment of the benefits and protections of that state's laws.

When an online retailer intentionally markets its products or services to residents of a particular state, engages in transactions with those residents, or directs its activities toward that state, the retailer can reasonably anticipate being haled into court in that state. This targeting can be evidenced through various means, such as advertising, online promotions, or even the design of the website that is accessible to consumers in that state.

The other options contain conditions that do not necessarily establish specific jurisdiction. For instance, having a physical storefront or a corporate headquarters in the state contributes to general jurisdiction but may not be required for specific jurisdiction, which is primarily focused on the relationship between the defendant's conduct and the forum state. Being based in a different country does not inherently negate jurisdiction; rather, it depends on how the retailer interacts with the forum state.