One of the main challenges analyzing your ad data is finding the right resolution.
If you are looking at location data, is it better to compare city by city or country by country?
If you are looking at performance data, is it better to look at the campaign’s lifetime results or just the past week’s?
This is the time when looking at the forest doesn’t work, and you need to look at each individual tree.
If you are looking at different promotion campaigns, where the ads are different from each other, looking at the lifetime data won’t work.
Same is true if you are targetting different promotions to different cities: comparing performance country by country won’t have much meaning.
Set the boundaries from your ad creatives and your intended audiences. Then you can get the right resolution for your data.