Estimates of the US penetration levels of mobile phone users have reached ninety percent from some organizations, but eMarketer released new information today that cuts that figure by nearly fourteen percent and over forty million people. The study on US mobile phone users and penetration levels estimates in 2008 counts 228.2 million people, about 75 percent of the population. This year, the figure reached 235 million at 76.5 percent, projected to rise each year through 2013 to 80 percent - 255.4 million people. These figures are lower than those from CTIA, The Wireless Association. According to eMarketer, the CTIA's figures count 276.61 million in June 2009, which would be equal to ninety percent of US population.

The discrepancy lies in counting the number of subscriptions on wireless carriers, rather than individual subscribers. In the case where a person may have more than one phone line, the CTIA would have counted two, whereas the eMarketer report aims to count only the one.

The former's rates are problematic not only because they are inaccurate, but they eventually exceed one hundred percent of the population. Using the alternate strategy of counting mobile phone ownership, eMarketer intended to construct a closer proxy for actual mobile users. With this method, projected penetration levels do not reach ninety percent until around 2020.

Taking data from various sources, the same article showed ownership for mobile phone owners to be around 79 percent from both Ipsos MediaCT and the New Millennium Research Council in 2008, but only for adults aged eighteen and up. For teenage ownership, a Nielsen Company report showed 77 percent of US thirteen-to-seventeen-year-olds owned a cell phone.

For another confirmation of eMarketer's low mobile user estimate, comScore recorded 233 million mobile phone users in May 2009. If such figures are correct, debates in progress related to limited spectrum and other wireless issues may need rethinking.