• by Joe Mandese  @mp_joemandese, February 22, 2016

Following normal seasonal patterns, demand for advertising inventory crashed in January following one of the strongest Decembers ever recorded, but on a January-to-January basis, it represents the strongest start of a new year since Standard Media Index began tracking U.S. ad marketplace volume.

The U.S. Ad Market Tracker index fell 75 points to a 163 in January from a 238 in December 2015. But year-over-year, January’s trading volume was up six points over January 2014, and is the strongest January since the index began in 2010.

The falloff was most pronounced among smaller advertisers and ad categories, as the Top 10 category index held more of its index value coming into the new year.

The top 10 categories fell to an index of 176 in January from a 249 in December 2015, while smaller categories ranked 11+ fell to an index of 136 from 222 during the same month-to-month period.

On a year-over-year basis, the top 10 categories are trading 5% greater volume than in January 2014, while the 11+ categories are down 4%.