When building a 3rd Party audience to use for your Performance TV campaign, you will note that Audience Size for any specified set of criteria is an estimation of household reach.
3rd Party audience data is an estimation of your potential household reach. The audience size shows the total number of households that are linked across all audience categories you are selecting for your 3rd Party Audience.
There are many considerations to make when choosing your audience. Your Customer Success Manager will be able to help you plan your budget against audience reach.
For Performance Television
Audience categories are not filtered specifically for OTT (Over the Top) devices that would be targeted exclusively for Living Room Quality inventory. So specifically, these estimations do not reflect "TV only" households.
However, it's important to note that Living Room Quality™️ campaigns will still only serve to OTT devices that fit within the 3rd Party Audience definition you have created.
There are no implications. Your 1st Party (retargeting) audiences directly reflect data that is being collected through your installed tracking pixel and IP address.