Advertisers who buy cable locally need to know that local cable commercials are not seen in the majority of ADS homes. To get an accurate reach of a local cable ad schedule in these markets, the ADS percentage of the audience must be deducted if they are included in cable’s ratings submissions.
According to Nielsen data, national ADS penetration is currently at 30.2% of television households. Many individual markets have even higher ADS penetration.
Here is a look at an example in the Harrisburg-Lancaster-Lebanon-York, PA market. When ADS is deducted, ad-supported cable delivers a fraction of the "All Cable" rating:
How Do Advertisers Reach Viewers
in Harrisburg-Lancaster-Lebanon-York, PA?
Cable reaches 63.3% of TV Homes, but reach diminishes
depending on the cable interconnect
Source: The Nielsen Company, May 2016
Make sure your local cable buys are based on the right data. Be aware of ADS.