Now you can capture Order IDs to mitigate double-conversion counting in AdWords

If a customer converts from an AdWords ad and revisits the confirmation page to find information about their order, you definitely don’t want that page load getting counted as a new conversion. Now, order IDs can be used to help ensure a conversion isn’t counted more than once.

Tuesday, it was announced that advertisers now can edit their conversion tags to capture an order ID, such as a confirmation number, order number and so on. When a customer revisits that conversion page from the same device they converted on, AdWords will filter out the duplicate.

There are a few things you’ll have to do get this going:

1. Set up an AdWords conversion tracking tag. This kind of goes without saying, but you will need to set up a conversion action and have the conversion tag placed on your website to have anything to de-dupe in the first place.
2. Capture some type of ID with your conversions. You’ll need to capture an order number or some kind of unique identifier when a user completes a transaction. Numbers, letters, dashes and spaces are all acceptable — up to 64 characters — as long as you’re not pulling in any info that could be used to identify a customer, like a last name.
3. Be able to add code to the AdWords conversion tracking tag. The code is what inserts the order ID in the conversion tracking. If you’re not a developer, you’ll probably want to ask one to help you out at this stage.

The instructions for adding the code to the conversion tracking tag are available on this AdWords support page.