The US Center for Disease Control tracks the number of mobile-only and mostly mobile households. Today 30% of US homes have no landline with an additional percentage making and receiving most of their calls via mobile. In that scenario the landline becomes a kind of "spamcatcher" reserved for telemarketers and fundraising calls.
The combined number of mobile-only and mostly mobile homes in the US is now above 45%. That's an amazing statistic if you think about it.
An analogous, emerging statistic is the number of people who primarily access the Internet on their mobile phones. This morning the Pew Internet Project published survey data that show 17% of all mobile phone owners use their phones as their primary Internet access device. However, if the population is narrowed to all mobile phone owners who access the mobile Internet (55% of mobile phone owners according to Pew) the "primarily mobile" percentage jumps to 31%.
In other words, according to Pew, "31% of these current cell internet users say that they mostly go online using their cell phone, and not using some other device such as a desktop or laptop computer." Even more striking, 45% of 18-29 year olds who access the Internet on their phones are in this "primarily mobile" category.
We found previously (n=1,504) that 17.6% of Internet users went online primarily via a non-PC device (smartphone/tablet). Regardless, these numbers will will only grow larger over time.