• by Joe Mandese  @mp_joemandese, December 30, 2015

The supply of unique users available on mobile or computer screens fell to its lowest point this year on Christmas Day, according to a new daily digital media traffic index introduced last month by MediaPost and Jumpshot. The index, the first to estimate the daily supply of unique users, pages viewed and time spent across all Web and mobile screens, fell to an 84.6 on Dec. 25th, suggesting that American digital media users were more interested in bonding face-to-face than on Facebook, Facetime, or another digital interface.

The next-lowest supply of the year occurred on Jan. 14, when the index fell to 91.5. The highest point of 2015 was on April 15, when the index soared to 130.9, most likely due to last-minute digital filing by American taxpayers.

If Americans were connecting digitally on Christmas Day, it most likely was via mobile device -- possibly even one opened on Christmas morning -- as the supply of unique users fell much more significantly among computer users vs. mobile users, although both also hit their annual lows.

The supply of unique computer users available online declined to 67.9 on Christmas, which compares to the next-lowest day of the year, July 4th, which had an index of 70.4. The greatest supply of unique computer users available online also occurred on tax deadline day, on which the index soared to 151.6. The days leading up to April 15 also had among the highest supply of unique computer users available during 2015.

While the availability of mobile unique users remained high relative to computer users, it also fell to its lowest point of the year, hitting an 88.9 on Christmas Day. The next-lowest supply of mobile uniques occurred on Jan. 18, when the index fell to 97.6.

Interestingly, the greatest supply of mobile unique users was not on April 15, which while near the annual high with an index of 115.4, trailed the highest day of the year -- June 21 -- by five index points.