Definition
Analytics tools use the broad meaning: Google, Facebook, direct, referral. Media buyers add a narrower one. Inside an ad network, every publisher site or app placement has an identifier, the source ID, sub-ID or zone ID depending on the network, and that identifier is passed to the advertiser's tracker on every click. Two sources in the same GEO can differ tenfold in conversion rate, so the source ID, not the GEO, is where most optimization happens.
Types of traffic source
| Type | Examples | How it is bought |
|---|---|---|
| Search | Google Ads, Bing Ads | CPC on keywords |
| Social | Meta, TikTok, X | CPM or CPC on audiences |
| Display and native networks | Ad networks, native platforms | CPM or CPC on placements |
| Pop and push networks | Pop, push, in-page push, redirects | CPM or CPC per GEO, optimized by source ID |
| Owned | Email, SMS, push lists | No media cost |
| Organic | SEO, referrals | Not bought |
How buyers optimize by source
- Pass the network's source macro to the tracker on every click.
- Run the campaign wide for the first days so every source gets a sample.
- Rank sources by cost per conversion once each has enough clicks to judge.
- Move converting sources to a whitelist campaign with a higher bid; add the rest to a blacklist.
- Keep a small broad campaign running to discover new sources as publishers join.
Source quality signals
Conversion rate against the offer, time on page and bounce rate on the landing page, the share of clicks the tracker flags as suspicious, and consistency over time. Networks pre-filter sources with fraud detection and publisher moderation, but the buyer's own conversion data is the final judge, which is why transparent source IDs are a condition for serious performance buying.
Related terms
| Term | Relation | Where defined |
|---|---|---|
| Media buying | The practice built on sources | Term page |
| Ad network | Aggregates sources | Term page |
| Web traffic | What sources deliver | Term page |
| Postback URL | How conversions are tied back to sources | Term page |
FAQ
What is a source ID?
The identifier an ad network assigns to a publisher placement. It is passed to your tracker through a macro on every click so you can measure each placement separately.
What is the difference between a traffic source and a channel?
In analytics they are near-synonyms; in media buying a channel is the format or platform (pop, push, search) and a source is a placement within it.
How many clicks do I need before judging a source?
It depends on the offer's conversion rate. A rule of thumb is to spend two to three times the offer payout per source before cutting it.