The Pontiac algorithm optimizes your campaign based on the selected Key Performance Indicator (KPI):

• CTR (Click Through Rate): Select this KPI if your goal is to increase clicks and drive more traffic to a site. Calculation: Clicks ÷ Total Impressions.
• CPA (Cost Per Acquisition): Select this KPI if you are trying to decrease the cost per conversion on the campaign. Calculation: Campaign Cost ÷ Number of Conversions.
• vCTR (Viewable Click Through Rate): Select this KPI to increase the number of clicks on viewable ads. Calculation: Clicks ÷ Viewable Impressions.
• Viewability: Select this KPI to maximize the viewability of your campaign. Per IAB guidelines, an ad is considered Viewable if 50% of the pixels are in-view for 1 second or more. Calculation: Viewable Impressions ÷ Total Impressions Served.
• VCR (Video Completion Rate): Select this KPI for video campaigns to optimize for completed video views. Calculation: Video Completions ÷ Total Videos Served.
• Reach: Select this KPI to attempt to spend the entire allocated budget without optimizing to a specific performance metric.

For KPI recommendations by Product see here: Product Offerings & Targeting Strategies.