The vocabulary of agentic marketing, defined.

Plain-English definitions of conversion tracking, marketing measurement, and agentic marketing terms — each one an atomic answer linking to where it goes deeper.

C

Click ID (gclid / fbclid / wbraid)

A click ID is a unique, platform-written URL parameter identifying one ad click: gclid (Google), fbclid (Meta), wbraid/gbraid, msclkid, ttclid. It's the match key of paid-media measurement.

Consent mode (v2)

Google consent mode is the API that tells Google tags what a visitor consented to; v2 added the ad_user_data and ad_personalization signals required for EEA measurement since March 2024.

Conversions API (CAPI)

The Conversions API is Meta's server-to-server channel for conversion events: a second transport for the same events the pixel sends, not a replacement for it.

Cookie lifetime is how long a cookie actually survives in the browser. Safari's Intelligent Tracking Prevention caps it at 7 days (sometimes 24 hours) for script-set cookies, silently shortening attribution windows.

Cookieless tracking

Cookieless tracking is the umbrella for measurement that doesn't depend on third-party cookies: first-party data, server-side event streams, hashed-identifier matching, and modeled conversions.

Cross-domain tracking

Cross-domain tracking keeps one visitor recognized as one session when they move between domains you own (typically site to checkout) by passing the identifier across the domain boundary.

E

Enhanced conversions

Enhanced conversions is a Google Ads feature that sends SHA-256-hashed first-party data (email, name, phone) with your conversion tags, so Google can match conversions to signed-in accounts that cookies alone lose.

F

First-party data

First-party data is the data you collect from your own audience through your own surfaces (site events, CRM records, order history) under your direct relationship and consent.

I

Identity resolution

Identity resolution (user stitching) connects events and records carrying different identifiers (hashed email, user ID, click ID, device ID) into one person, so marketing data can be matched across sources.

L

LTV & LTV:CAC ratio

Customer lifetime value (LTV) is the total value a customer generates over the relationship; the LTV:CAC ratio compares it to acquisition cost. For marketers, LTV is a bidding input, not a finance vanity metric.

M

Meta pixel

The Meta pixel is Meta's JavaScript snippet that reports website events (PageView, Purchase, Lead) from the visitor's browser to Meta for ad targeting, measurement, and optimization.

O

Offline conversions

Offline conversions are conversions that complete away from your website (a deal won in the CRM, a contract signed), imported back into the ad platform and joined to the original click by click ID or hashed email.

S

Server-side tagging (sGTM)

Server-side tagging runs your tag manager in a cloud environment you own: one event stream in from your domain, fanned out to your ad and analytics platforms from your server. Infrastructure for server-side tracking, not the same thing as it.

Server-side tracking

Server-side tracking sends conversion and analytics events from a server you control instead of the visitor's browser: a more durable transport for the same events, not a way around consent.

Signal quality

Signal quality is the fitness of your conversion data as an input to automated bidding: complete, deduplicated, on time, and carrying real values.

Smart Bidding

Smart Bidding is Google Ads' auction-time automated bidding (Target CPA, Target ROAS, Maximize conversions, Maximize conversion value), setting a bid per auction from the conversion data you feed it.

T

The tracking bottleneck

The tracking bottleneck is the point where conversion signal quality caps everything downstream: bidding, attribution, and MMM can't be better than the data they're fed.

Third-party cookies

Third-party cookies are cookies set by a domain other than the site you're visiting: the mechanism behind cross-site ad targeting and view-through measurement, blocked by Safari and Firefox and retained by Chrome.

Tracking pixel

A tracking pixel is a tiny image or script that fires an HTTP request when a page loads or an event happens, carrying the URL, referrer, timestamp, and identifiers back to a collection server.

U

UTM parameters

UTM parameters are the standard URL query parameters (utm_source, utm_medium, utm_campaign, utm_term, utm_content) you append to links so analytics tools can attribute the visit to its campaign.

V

Value-based bidding

Value-based bidding is automated bidding that optimizes toward conversion value instead of conversion count (tROAS and Maximize conversion value on Google Ads), and it's only as good as the values you feed it.