The Team here at Stellar Search have access to numerous different AdWords accounts thanks to our ever gorwing client portfolio and something we have been seeing more and more of recently is what we are calling the 'Google AdWords Midnight Glitch.'This is where there is a spike in impression at midnight on campaigns which makes no real sense in so far as the number of people searching at that time. Have a look at the screenshot below and you'll see how there are nearly double the amount of impressions at midnight than there is at 11pm and three times the amount a 1am...

Now when we first saw this on one of our accounts, we thought it might just be that there was more people searching at Midnight than at other times...but really...is that the case? We've noticed this happening on a number of our accounts advertising across different verticals, so we think it is one of either two things...1. There are more automated bots spidering ads at Midnight than at any other times (the developers have set them to run at Midnight each day) and this is what is increasing the amount of impressions.2. AdWords is spiking campaign traffic at this time, entering ads into more auctions at Midnight as it resets the daily caps for campaigns at Midnight. As a result, AdWords is trying to show ads as much as possible whilst it learns how many impressions/clicks the campaign is receiving so that it can then decrease the number of auctions ads are entered into (on Broad and Phrase match) in order to spread budget across the day.Recommendation: Have a look on the dimensions tab of your campaigns and see if you are getting a spike in impressions at Midnight. If so, try using ad scheduling away from Midnight and you should see this impression spike go away.A tip from the Stellar Search Team.