How are traffic sources are defined in PixelFlow?

Every visit to your site is assigned to exactly one traffic source — Facebook, Google, TikTok, Organic, Direct, and so on. You'll see the source in the Attribution funnel table, the Source column in event logs, and the Came from column in Conversions Journeys. This article explains how a visit gets its source, what each source includes, and how to make the assignment more precise.

How a visit is assigned to a source

PixelFlow checks signals in order and uses the first one that matches, so an ad click always wins over a campaign tag or a referrer.

1. Ad click IDs in the URL — tracking parameters that ad platforms add to links: gclid (Google), ttclid (TikTok), li_fat_id (LinkedIn), and msclkid (Microsoft / Bing).

2. The utm_source parameter — read from the link the visitor clicked. For example, utm_source=google counts as Google and utm_source=facebook counts as Facebook.

3. Remembered ad clicks — a returning visitor who first arrived through a Facebook ad keeps the Facebook source via the persisted fbc value, even when the click ID is no longer in the URL.

4. Referring website — a nonblank referrer hostname counts as Organic. This includes search engines, other websites, and AI assistants such as ChatGPT, Perplexity, or Claude, which have no dedicated source.

5. No signal at all — the visit counts as Direct: the visitor typed your address, used a bookmark, or opened the site with no outside link we could detect.

Because click IDs are checked first, an ad click is always credited to the ad platform — even if the visitor found the link somewhere else later.

Every source, explained

Matching on utm_source is case-insensitive and prefix-based, so a value that starts with a channel's keyword counts for that channel. The table lists the common values for each source.

Move traffic into the right source with UTM tags

The utm_source parameter is the most reliable signal you control. Tag every link you share — ads, emails, social posts, partner links — with a UTM source that maps to the channel you want.

https://yourstore.com/?utm_source=facebook&utm_medium=social&utm_campaign=spring_sale

• utm_source=facebook → counts as Facebook

• utm_source=google → counts as Google

• utm_source=partner_blog → counts as Other, visible with its raw value in the event logs

For the full campaign → ad set → ad drill-down in Attribution, see How to use Attribution analytics.

Inspect a single visit

To see which signal decided the source for one event, open the event logs and check the Traffic Source and Payload views — they show the source that was assigned and the campaign details captured for that event.