The expanding growth of cell phone-only households has fueled debate over how best to include such households in telephone surveys. The latest cell phone-only estimate places the percentage at 20.2 percent (Blumberg and Luke, 2009). The Pew Internet and American Life Project predicts that mobile phones will become the primary connection to the Internet for most people in the world by 2020 (Pew, 2008).  Another Pew report suggests serious attention is now turning back to mail, either as a mode for surveying cell-only households or as a contact strategy for recruiting such households to Internet surveys (Pew, 2007).