Be sure to insist on HOURLY reports/analytics
If you get DAILY reports, you can't see if all your ads may have been used up between 12 - 4a when humans are asleep.
15 years of data, plus this latest report from AdAge data center, shows that humans use the Internet, social media, mobile devices, etc. when they are awake. (Common sense could have told you that too) ;-)
So when should you run your ads? Right, when humans are awake and using devices and going online. You can safely turn off the hours of 1a - 4a or reduce your bids during those hours, when most humans are sleeping.
How can you check? You should insist on reports and analytics that show you HOURLY volumes; without it you won’t be able to see that your ads are blown out between 12a - 4a, leaving you no impressions to show during waking hours. See #FouAnalytics chart below — green bars show hourly volumes. You can see in the four days on the left, all the impressions were blown out at midnight; the 5 days on the right side of the chart shows most of the impressions used up between midnight and 4a, leaving no volume during waking hours.
Another chart from #FouAnalytics below shows a well-managed campaign where low to no ad impressions were wasted in the overnight hours (see green volume bars). The hourly volume of ads served mirrors well the waking hours in which humans are online, using social media, and on their devices. Also, don’t be scared about the red spikes in those hours — that is the stacked percentage and when most of the volume is gone, the bots that remain make up the majority of the impressions measured.
Even more zoomed in chart, so you can see the hourly volume (green bars) details.
Read more at http://fouanalytics.com/
How to get hourly reports in Google Analytics - https://www.slideshare.net/augustinefou/checking-abnormal-referrer-traffic-in-google-analytics