In order to make the most of Google's machine learning, you should set up Conversion Tracking for your advertising campaigns.
This will enable Google to track conversions (sales) on your eCommerce store and allow Google Ads to determine how best to achieve your advertising goal for your ads and record ad performance information.
There are two ways to set up conversion tracking in your Google Ads account. You can either import them from Google Analytics, or you can install Google Ads Conversion Tag on your site (recommended).
Import Google Analytics
This is the simplest method, but you will miss out on some of the inputs to machine learning as the conversions are only imported using your configured attribution model in Google Analytics. To set it up, follow the instructions to Import Analytics goals and transactions into Google Ads Conversion Tracking.
Google Ads Conversion Tag
This is the method that we recommend due to the fact that you get a better result from machine learning bidding strategies using this tag. To set it up follow the instructions in the Set up conversion tracking for your website support article. Also, we strongly recommend using the Option 2: Google Tag Manager approach as this gives you more flexibility in regards to other tags on your website in future.
When setting this up, make sure you pass the total value of the purchase so that Google knows the value of the transaction to your business.
Our team are very experienced in setting up conversion tracking for eCommerce websites, so we can do it for you for a fee. Contact us for more information.