When reviewing the performance of your Google Ad Campaign, you have a lot of choices. You can view today, yesterday, last 7 days, last week, this week, last 30 days, last month, all time, etc. While there is a time and place to view all of them, which view should be you looking at when making optimizations to your campaign? When I say optimizations, I mean changing keyword match types or pausing keywords based on how many conversion they received, excluding or making bid adjustments on certain demographics and audiences based on how many conversions they have received, excluding or making bid adjustments on locations based on how many conversions they have received, pausing underperforming ads, etc.

For these types of optimizations, I like to review "All Time" data since it gives me more statistically significant data. Smaller datasets aren't statistically significant so you don't want to read too much in the results since they could simply be due to chance.

There are exceptions to this like if your conversion tracking changed while your campaign has been running, in which case conversion data before a certain time and date can't be trusted, therefore viewing "All Time" data would be a bad idea. Also sometimes I'll do a full reset on bid adjustments, exclusions and/or bid strategy just to see how it will impact campaign performance. In this case, it's similar to starting a new campaign and I'll just adjust from that date onward.