Finding the Perfect Fit
People always ask me, "Which date range should I use when making bid adjustments?"
The answer: it depends.
More specifically, the "correct date range" is going to be different every time you optimize. To get the best range, you have to...
Think it through!
Imagine it's January 1st.
Do you really want to calculate bids based on performance from the last 30 or 60 days when conversion rates were inflated through the holidays?
Probably not.
If you did, your bid calculations would likely be too high relative to the performance we typically see after the holidays.
In order to get your bids more attuned to recent performance trends, you'd probably want to look at December 24th - December 31st, when most of the shopping craze dropped off. In this instance, we're exchanging data confidence (i.e., high volume of clicks and sales over long periods of time) with data relevance (i.e., recent trends).
By January 7th, you could expand that date range to include December 24th - January 6th, which would increase your data confidence while still maintaining relevance to recent performance.
As you can see, the date ranges we select are dynamic and should be adjusted upon every iteration. So rather than asking "What's the right date range," the question becomes, "How should I be thinking about date range as a data sourcing tool?"
General Guidelines
After thinking through date range as a data source, here are the ranges I find myself using:
Less than 7 days - Very rare! I only use this short a timeframe when responding to a major sudden change in CVR (e.g., during or immediately after Prime Day)
Last 7 to 14 days - More commonly used to account for shifting trends in CVR (e.g., season products beginning to enter their peak seasonality)
Last 30 days - All around a good "default" date range to use for general PPC management
Last 60+ days - Best for accounts that generally have low volume on individual keywords or products; selecting a longer date range can help consolidate some larger numbers for more accurate bidding
The most important thing is to select a date range with performance similar to what you expect will happen in the near future!
Feel free to send us a message if you have any questions :)
For a more in-depth discussion on date range selection, see our other article here.