Anyone who comes to asian countries realizes quickly when they have only a few pages left in their passport , how Cambo and Vietnam for example can take 1 page per entry and two if you get an extension . The e visa is available for for a thirty day stay , and apparently you can renw the evisa once for an additional 30 days within the country . ( cambodia) an American can have additional pages placed in their passport but many cannot .So this is an good way of saving pages in your passport if u are running low !