The first two weekends of NFL Playoffs football dropped 3% in viewership from a year ago -- to 31.6 million from 32.5 million, per Nielsen data.

The most-viewed game this year was the the divisional playoff game between the Dallas Cowboys and San Francisco 49ers -- coming in at 45.7 million viewers.

The NFL pulled in an estimated $1.1 billion in national TV advertising revenue, offering marketers 17.7 billion impressions, according to iSpot.tv.

National TV revenue a year ago amounted to $1.2 billion, with total impressions at 26.2 billion. The top paid advertisers were Verizon ($50.6 million), Progressive Insurance ($36.7 million), Chevrolet ($25.40 million) and Geico ($25.35 million).

The “attention” index for all national TV ads, as measured by iSpot for these ads, was 66.

iSpot.tv says this “attention” number has a 100 index as average. A year ago, attention for all NFL ads for the first two weeks averaged 112.

The best result for attention this year was a CBS on-air promo for its reality competition show “Tough As Nails,” earning a 174 attention index. The best paid ad this year came from Intuit, for its “Every Dream Deserves a Chance” spot at 167.