Glossary

Ad tracking, in plain words

The terms you meet when you set up server-side tracking, conversion APIs and ad reporting.

Server-side tracking: Sending conversion events to an ad or analytics platform from a server over its official API, instead of only from a script in the shopper's browser. It is not blocked by ad blockers and does not depend on the shopper staying on the page.
Conversions API (CAPI): Meta's server-to-server API for sending website, app, chat and offline conversions to a dataset (the same one the Meta Pixel uses). Used for Facebook, Instagram and WhatsApp ads. TikTok, Snapchat, Pinterest, LinkedIn and X have their own versions.
Meta Pixel: Meta's browser script (fbq) that sends events from the shopper's browser. Running it together with the Conversions API and the same event id is Meta's recommended setup.
Deduplication: Keeping one copy of an event that arrived more than once, for example from the browser and the server. Meta and TikTok match on event name + event_id within 48 hours; GA4 deduplicates purchases by transaction_id.
event_id: A unique id for one event, sent identically by the browser and the server so the platform can drop the duplicate. For purchases, derive it from the order id, for example purchase_10023.
First-party cookie: A cookie set on the store's own domain. Tracking ids stored this way (visitor id, click ids) are not affected by third-party cookie blocking.
First-party tracking domain: A subdomain of the store (such as track.yourstore.com) that serves the tracking script and receives events, set up with one CNAME record.
fbclid: The click id Meta adds to landing-page URLs when someone clicks a Facebook or Instagram ad. Stored in the _fbc cookie as fb.1.{time}.{fbclid} and sent to the Conversions API as fbc.
_fbp: Meta's browser id cookie (fb.1.{time}.{random}). Sent with server events to help Meta match them to the browser.
ttclid and _ttp: TikTok's click id (added to landing URLs by TikTok ads) and browser cookie. Both are sent unhashed to the TikTok Events API.
gclid, gbraid, wbraid: Google Ads click ids added to landing URLs. gbraid and wbraid are used for iOS traffic where gclid is limited.
ctwa_clid: The click id of a click-to-WhatsApp ad, delivered in the referral of the customer's first message through the WhatsApp Business Platform. With it, a chat order can be sent to Meta as a business messaging conversion.
Hashing (SHA-256): Turning an email or phone into a fixed 64-character fingerprint before sending it. The platform hashes its own users' details the same way to find a match, without the raw value being shared. Formatting must match exactly: Meta wants phones as digits with the country code, TikTok and Google want E.164 with a plus sign.
Event Match Quality (EMQ): Meta's score for how well the customer details on an event help it find the matching account. More identifiers (email, phone, fbc, fbp, IP, user agent) usually means a higher score.
Measurement Protocol: Google Analytics 4's API for sending events from a server. It accepts events up to 72 hours old and answers with success even for invalid events, so validation matters.
ROAS: Return on ad spend: revenue divided by ad spend. A ROAS of 3 means 3 taka of revenue for every 1 taka spent. Compare it with your margin: below 1 ÷ margin you lose money on ads.
CPA / cost per order: Ad spend divided by the number of orders in the same period.
CTR and CPC: Click-through rate is clicks divided by impressions; cost per click is spend divided by clicks.
Conversion rate: Orders divided by sessions: the share of visits that end in an order.
Last-touch attribution: Giving credit for an order to the last ad click or campaign the shopper came from before buying.
View-through conversion: A conversion an ad platform credits to an ad the person saw but did not click. It is one reason platforms report more purchases than a store's own last-click count.
Consent mode: Respecting the shopper's choice for analytics and advertising. With ads consent denied, no ad cookies are set and nothing is sent to ad platforms.
Cash on delivery (COD) purchase trigger: The order status at which a COD order is reported as a purchase: when placed, when confirmed, or when delivered. Pick one and keep it stable so the ad platform learns from a consistent signal.
Business messaging conversion: A Meta conversion that happened in a WhatsApp, Messenger or Instagram chat after a click-to-message ad, sent with action_source business_messaging and the chat's ids.

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