Advanced Attribution: Storing Click IDs in Your CRM

Ad platforms report clicks and form fills. Your CRM knows which of those leads became customers. Click IDs are the link between the two: store them with each lead, and you can tell the ad platforms which clicks turned into revenue.

This guide is the companion to Your Google Ads Are Converting. You Just Can’t See It., which covers getting the conversions themselves back into Google Ads.

Click IDs connect a CRM record to the ad click that started it

Say you sell handmade jewelry and run ads on Meta and Google. Your analytics can show how many visits each campaign sent. It can’t show which of those visitors bought six weeks later after a phone call with your team.

When someone clicks an ad, the platform adds a unique click ID to the landing page URL. Your site can save that ID in a first-party cookie and pass it into the CRM with the lead. When the lead later becomes a customer, you send the conversion back with the click ID, and the platform matches it to the original click, campaign and keyword.

What this gives you:

• Which campaigns produce customers, not just leads. Conversions sent from the CRM can be the sale or the qualified lead, so you can compare campaigns by what happened after the form.
• Better lead quality signals. Some sources send many leads that never buy. Click IDs on CRM records let you see that and adjust targeting.
• A clearer view of each customer’s path. The click ID sits on the contact record next to the rest of their history, so sales and marketing look at the same record.

Some conversions will still go unmatched: people switch devices, clear cookies or arrive without a click ID. Storing click IDs narrows that gap; it doesn’t close it.

Google uses three click IDs and Meta uses one

These are the URL parameters to capture on the landing page:

• gclid (Google Ads): added to the landing page URL when auto-tagging is on. Google’s conversion linker tag saves it in the _gcl_aw first-party cookie.
• gbraid and wbraid (Google Ads): used instead of gclid on some iOS traffic, where Google can’t use a gclid. Capture and store them the same way; Google’s offline conversion imports accept them.
• fbclid (Meta): added to links clicked from Facebook and Instagram. The Meta Pixel saves it in the _fbc cookie, which the Conversions API accepts as the click ID.

Save the parameter from the URL into a hidden form field (or read it from the cookie) so it lands on the CRM record with the lead.

Server-side GTM can send CRM conversions back to the ad platforms

Once the click ID is on the CRM record, you need a way to send customer actions (a closed deal, a qualified lead) back to Google Ads and Meta. One common way is Google Tag Manager Server-Side (sGTM):

1. Set up a server container: create a server container in Google Tag Manager and host it on your own subdomain. Events then reach the platforms from your server instead of from the visitor’s browser.
2. Trigger an event in the CRM: when a lead reaches the stage you care about (for example, a closed sale), the CRM fires an event that includes the stored click ID.
3. Send it by webhook: the CRM sends that event, with the click ID, to your server container.
4. Configure the tags: inside the server container, a tag for each platform (Google Ads, Meta Conversions API) passes the click ID and conversion details to that platform.

Send conversions inside the attribution window, and only for leads that matter

• Attribution windows: each platform only credits a conversion to a click within a set window. Meta’s default is 7 days after the click; Google Ads lets you set the click window per conversion action. Check the window you use against your sales cycle: a conversion sent after the window closes isn’t credited to the ad.
• Optimize for valuable leads: with click IDs in the CRM, you can send conversions only for leads that reached a qualified stage or became customers. The platforms then bid toward people who look like your buyers, not everyone who filled in a form.