Your client is running a branding campaign on TV and wants to increase their online...

Facebook TRP Buying has the following benefits primarily:

Incremental Target Audience Reached: Measured across 42 US campaigns, when TV and Facebook were combined, advertisers saw a 19% increase in targeted reach versus TV alone. When Millennials were the target audience, incremental reach increased to 37%.

Efficiency: Across the same 42 campaigns, Facebook impressions were two times more likely to hit their target audience than TV impressions. This means advertisers spent less to reach their target audiences.

Effectiveness: A study by Nielsen of seven recent campaigns showed that, compared to people who saw TV alone, people exposed to both TV and Facebook demonstrated a 3.2 percentage point increase in ad memorability, 11.5 percentage point increase in brand linkage, and a 22.7 percentage point increase in like-ability linkage.

Measure Traditional Campaigns: With Facebook TRP buying, advertisers can measure traditional channels with online channels equally through third-party providers. 

Facebook currently partnered with Nielsen Digital Ad Ratings in order to verify on-target impressions. Keep in mind that all TV marketing efforts that run in conjunction with Facebook TRP buying ads should be geared towards branding campaigns, not direct response campaigns.