Initially, direct selling was achieved through mailings and telephone contacts, but since the mid-1990s the majority of Dell's sales have been made over the Internet, and by 2004, some 85 percent of all sales were made through this medium. Internet selling has enabled Dell to offer its customers the ability to customize their orders, mixing and matching product features such as microprocessors, memory, monitors, internal hard drives, CD and DVD drives, keyboard and mouse format, and the like, to get the system that best suits their particular requirements.