The short answer
A conversion is a valuable action a customer takes, such as a purchase, a sign-up or a call. Google Ads can only tell you which keywords and ads are working if you tell it what counts as a conversion.1 For most service businesses that means a completed enquiry form or a phone call.
Why it matters
Google lists several reasons to track conversions: you can see which keywords and ads perform best, understand your return on spend, let automated bidding optimise towards real results, and see conversions across devices.1 Without it, an ad that brings lots of clicks and no customers looks identical to one that brings a customer every day.
The four things you can track
- Website conversions: actions such as purchases and sign-ups, recorded through a snippet of code on your site.1
- App conversions: installs and in-app actions.1
- Phone call conversions: calls from your ads or from a phone number on your website.1
- Offline conversions: sales you record in a CRM or spreadsheet and upload later.1
For most small businesses, website conversions (the enquiry form) and calls are the ones that matter. If most of your sales happen after a conversation, offline conversions let you tell Google which enquiries became paying customers.
A simple setup
- Decide what counts. One or two main actions, such as "enquiry sent" and "call from the site".
- Choose a data source. Google describes setup as choosing your data source, which is either Google Analytics or the Google tag, then grouping your conversions into actions and finishing the configuration.1 If you already mark enquiries as key events in Google Analytics, you can create Google Ads conversions from them.2
- Mark the main actions as primary. Google says conversions should be set as primary or secondary correctly, because primary ones are used for bidding.1
- Test it. Send a test enquiry and check the conversion shows up. Give it a day, since reports are not always instant.
- Look at it weekly. Check which campaigns and keywords produce conversions, and shift spend towards them.
A note on consent
Google notes that tracking needs user consent where the law requires it.1 Your privacy policy should say what you track and why. See NZ marketing rules.
What to do next
Tracking is the first thing I set up on any ads account. If you want to understand your analytics side as well, read my guide to tracking website enquiries, and see how I run ads.
References
- About conversion measurement. Google Ads Help. Accessed 5 October 2026.
- About key events. Google Analytics Help. Accessed 5 October 2026.