Upon clicking on and opening a Line Item you will see a section called ‘Flight Metrics’ above the configuration menu. This section will display metrics for the line from start date to ‘yesterday’, changing the Reporting Interval will not change these metrics. These metrics are updated hourly with a 3 hour delay.

Clicks: Number of clicks in the lifetime of the Line
Budget Type: Either imps or spend depending on how the Line was configured
Daily Budget: This will display either the dollar amount or the number of impressions that the Line will attempt to spend each day. This daily budget will incorporate your budget multiplier to estimate daily budget.
Campaign Count: The number of optimizations that have been made to the line
Pacing: This is the % of the Line’s budget that has been spent compared to the ideal pacing based on the set budget and flight dates. Ideally a Line should pace between 90-110%. For tips to improve pacing see here: Improving Pacing.
Total Imps Served: The total number of impressions that the Line has served to date
Spend: Total dollar amount the Line has spent to date
View Measured Imps: Number of impressions that are measured for viewability by the publisher
Viewable Imps: Number of impressions that were registered as viewable. This means that 50% of the Creative was viewable for at least 1 second. Edit the Line Targeting parameters to include a viewability threshold to improve viewability.
Post Click Convs: The total number of post-click conversions driven by this Line to date
Post View Convs: The total number of post-view conversions driven by this Line to date
Last Opt Date: This is the date of the most recent optimization made to the Line Item
Performance: This will display the performance of the Line Item in relation to the selected KPI. If you are optimizing to CTR, performance will display the lifetime CTR for the Line. If you are optimizing to CPA, performance will display the lifetime CPA in dollars