Spend to date is calculated differently between the Performance Overview section of the dashboard and the campaign dashboard.
The performance overview section of the dash looks at the CPM for each line item when calculating the spend to date. Each line item is then added together to determine the spend to date.
Spend to date at the campaign level looks at the average eCPM for the campaign as a whole. For example, if the total cost of your campaign is $2k and the total number of impressions is 100,000 Podsights will apply a $20 CPM across the campaign to calculate spend to date rather than adding up each line item based on its individual CPM.
Spend to date is only calculated once campaigns have gone live. This is not calculated in advisor or media plans.