Three weeks into the new year, TV networks continue to pile on the advertising/promotion for their own shows, streaming efforts and other services, using their own airwaves -- up 4% in total media value/paid advertising, according to iSpot.tv, to $733.8 million.

However, overall national TV audience erosion has yielded lower impressions -- down 12% to 69.1 billion impressions from January 1 to January 23.

In an effort to gain back more impressions, TV networks overall lifted their paid advertising efforts -- buying time on other networks -- which rose to $82.7 million from $66.5 million.

Typically, at the start of the new year, TV networks look to ramp up promotion as the second half of the TV season delivers new programming for ongoing TV series.

Major NFL-partner networks also benefit from highly rated NFL playoff game viewership for entertainment program promotion.

Looking specifically at just the media value from promos airing on networks, this year the total grew slightly at 2% -- to $648.1 billion from $633.2 million. Overall, there was an increase in total promo airings to 443,700 from 430,026.

The top networks this year so far, in terms of impressions for their own brands, include CBS, (10.9 billion), followed by NBC (8.7 billion); Fox (7.5 billion); ABC (7.0 billion); HGTV (3.2 billion); Food Network (2.9 billion); and Discovery Channel (at 2.3 billion).

The top four broadcast networks benefit directly from high-performing NFL programming.

Top individual TV program promos since the start of the year include HBO’s “The Last of Us” (1.41 billion impressions), Fox’s “Alert: Missing Persons Unit” (1.38 billion), ABC’s “Will Trent” (1.28 billion) and NBC’s “Night Court” (1.26 billion).