Amazon PPC Management: How Often Should I Change Keyword Bids?

Rick Wong 6 December 2020

Amazon Pay-Per-Click (PPC) advertising is a very powerful marketing channel on Amazon. It enables the sellers to “buy” visibility for their products at the top of Amazon’s search results page. Understanding how to create PPC campaigns can save a great portion of money for the sellers. Knowing the ins and outs of Amazon PPC management and optimization is even more useful.

In this article, you will learn about one of the most important yet rarely asked questions when it comes to Amazon PPC. You would have guessed it from the title.

“How Often Should I Change Bids For Different Keywords On Amazon PPC?”

There are opinions out there, but rarely backed up by data and evidence.

To begin finding the answer to this question, we will start by finding what is the optimized timeframe.

Optimal Timeframe

To answer the question above, we did a study to look into the optimal timeframe to update keyword bids. When it comes to Amazon PPC management, using the correct timeframe for updating your bids and optimizing campaigns is key. For this, we downloaded a bulk file report of PPC from different accounts.

What is an Amazon Advertising Bulk File?

“Bulk file” is an Amazon advertising report that tells the performance of every keyword, campaign, ad group, and target for both sponsored products and sponsored brands in a particular time frame. These files are very convenient for Amazon PPC management and mass optimization. One file can update hundreds of campaigns and thousands of keywords at once.

Our Study on Optimal Timeframe

We downloaded a bulk file report for 7, 14, 21, and 30 date ranges. This data tells us how Amazon deals with the data in different periods of time. We did this for 3 accounts, as seen below.

Amazon PPC Management

You can do this with your own account. Check in the infographic below on how you can download these reports from your account. You can then use Microsoft Excel to convert the data into a pivot table and see the summarized data.

When we see the report above, we might not see anything uncommon… Everything seems straightforward. But when we check it in a little bit depth, we see some interesting facts.

If we see data for the last 7 days for the first account, we see the total spend like $13,317 with total sales of $58,756 and the advertising cost of sales (ACOS) is 23%.

Jumping to the last 14 days, the total spend is about $64,963 and the sum of sales accumulated is $276,195 with total ACOS at 24%.

Similarly, the total spend for the last 21 days is $29,607 and the sales are $133,674 with total ACOS at 22%.

Lastly, for the last 30 days, the total spend is $41,174, total sales are $180,432 with the total advertising cost of sales (ACOS) as 23%. You can see the data for the other 2 accounts in the sheet image above.

Amazon PPC Management

The Issue with Sales Data

In a perfect and ideal world of Amazon PPC advertising… There are no refunds, no delay in sales attribution, no promotions, and no percentage off sales. In a perfect world, we should see a linear increase in the total sales and total spend over time. So, when someone purchases a water bottle, a sale will be recorded on that day. Revenue will be also attributed to the keywords on the same day. In this idealistic case, we will see a linear increase in total sales and total spend.

Amazon PPC Management

When you look at the data, you see that the total sales and the total spending are not linearly increasing. The total spends for the last 14 days is $64,963 whereas the total spends for the last 21 days is $29,607. The spend for the last 21 days is around half of the total spend for the last 14 days.

Technically, when you see the spending for the last 21 days, the spending of the last 14 days is still there in the 21 days timeframe. Instead of showing an increase in spending, there is a gradual decrease in the spending in the last 21 and 30 days. There may be some glitch going on with Amazon bulk reporting system. So we analyzed the same trend with the other accounts that we checked. You can see this trend in the other two accounts’ data as well.

So, why are we seeing such unusual behaviour?

The factors behind this trend that we can consider for now can be…

Sales Attribution

Sales attribution is basically a delay in sales. This is possible that people click on your ad but instead of purchasing, they might add the product to the cart and purchase the product like 5 or 6 days later. Another possible reason is that they purchased the product as they clicked on the ad, but Amazon’s platform is taking some time to record the sale in its ad platform system. Having both reasons at the same time is also possible.


Amazon will deduce the total cost of the product for all the refunds made by customers. There can also be some delay in adding or subtracting the cost of these refunds from the total advertising sales. This can be the reason behind those drastic increases and decreases in sales for that certain period.

How This Study Helps Find The Optimal Time To Update Bids

Amazon PPC Management

Proper Amazon PPC optimization requires frequent keyword bid updates. Let’s say you usually update the bids based on the last 7 days’ data. You see a keyword or a campaign with 75% ACOS in the last 7 days, but what if Amazon’s PPC platform does not attribute all the sales data in the period of 7 days? Or if the refunds made during the past 7 days take some time when the total refund cost is deducted from the total accumulated sales?

Now how about using 14 day’s data? We checked in the study above it shows the total sales and the total spend for the last 14 days as twice as the total sales and spend for the last 21 days, which is why taking the decision based on 14 days is still not a great choice. The sales shown in the last 14 days are significantly high. We still need to collect more data before we take some wise action.

The decision cannot be taken in the last 21 days as the data is still fluctuating. So, the conclusion is obvious.

Another Study to Understand the Concept Deeper and Better

We performed another study to confirm the fact that the data is updated after some period on the Amazon advertising platform. The study shows that it takes more than 14 days or 21 days for Amazon to update the data.

What we did, for the straight 14 days, we noted down the total sales that were made on a single specific day.

On November 11th, we noted the total sales that were generated on November 10th i.e. one day ago. On November 12th, we noted the total sales for the same day i.e November 10th. So, for the 14 days, we recorded the total sales for the same day to understand how frequently Amazon updates the data. Please check the data in the following image:

Results of Study and Its Impact on Amazon PPC Management

We see that as we move ahead, the total sales number is changing. For some accounts, the change was up to 60% in the total sales and for others, the change was in negative percentage.

This confirmed the fact that Amazon takes some time, most probably more than 21 days, to update the data on its PPC platform. This is an important period to account for during Amazon PPC optimization and bid updates.

This second study shows that when you update the bids too early, especially for new campaigns, you may lose some of the extremely profitable keywords and you decrease the chances to get maximum profit from those keywords. But if you see that keyword like 3 or 4 weeks later, that keyword is performing really well and generating a significant amount of sales but for some reason, you decreased the bid.

This is the reason to understand sales attribution as it helps you understand how contextual time frames are for changing bids. Sales attribution also sets the basis for Amazon PPC optimization.

There might be other factors that change the ACOS or the number of sales, such as the holiday season. In that season, the buyability factor is high, the conversion rates are at their peak but after the holiday season is over, the conversion rates might come down and ACOS will be hitting the roof again.


It takes some time for Amazon to update all the data. For the keywords either performing outstanding or performing very slow, change the bids based on the last 30 days’ data. When it comes to Amazon PPC management, it’s better to change the bids when you have promising and rock-solid reliable data.

Apart from the time factor, there are many other factors that determine your success in Amazon advertising such as listing optimization, keywords selection, advertisement budget, etc. If you work on other factors and take less care of the timeframe, there is no doubt that you will get favorable results from Amazon advertising but it is better to take advantage of all the factors in order to achieve fortunate results.

The 30-days period is not a 100% optimal timeframe as we do not have a perfect and ideal Amazon PPC platform. However, 30 days is a standard timeframe in which, we saw, as a balance of using the most recent data, and data which can be relied upon, hence can be used to update the bids accordingly.

You can use this timeframe as a basis for future Amazon PPC management and campaign optimization. You can manage your campaigns manually, or save time and use Amazon PPC management software like ours to automate the process for you!

If you have questions or insights to share, please feel free to post them via the comments section. Please also consider joining our Facebook Group where we discuss any questions you may have about running an Amazon business.

We are SellerMetrics, our Amazon PPC Software helps Amazon sellers, brands, KDP Authors and agencies navigate Amazon Advertising PPC via bid automation, bulk manual bid changes, and analytics.




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