Users find a web-site or application in different ways: through search engines, social networks, adverts, etc. (traffic sources). There follows a procedure of data capture at IO. 


For data source definition the following input data is used:

  • Referrer: URL domain of the referring website.
  • UTM tags: GET parameters set automatically by IO algorithms in traffic generation systems (in case IO is integrated with corresponding paid / free traffic generation system) or set manually by the creators of acquisition campaign.

UTM tags are standard tags used by most traffic generation systems, e.g. :

  • source, utm_source
  • medium, utm_medium
  • campaign, utm_campaign
  • content, utm_content
  • term, utm_term
  • gclid (google adWords).


Information of traffic source is formed when transferring to the target resource page using input data described in point 1. and stored in pertinent internal structure. Sources are formed for each collected metric generated by visitor and used for further IO analytic algorithms.

Order of forming / changing source data:

  1. Source is checked for each user interaction - whether the user transfers from one page to another or fires the events on the same page (even if it is fired some time after the page was opened).
  2. Source change takes place with any parameters change from p.1. Exception - direct transferring (entry through site domain input on browser). See the final point of the current list.
  3. When opening a page of the same resource in the previously opened tab with a new source (new entry from a search engine, contextual advertising, etc.), any data on user actions in the previously opened tabs will be marked by sources received in the last one. 
  4. In case the entrance is not accompanied by utm_source tag, source parameter is replaced by referring domain name. Otherwise, value of сorresponding UTM tag defines the source (GET parameter of utm_source/source tag).
  5. In case the referrer is not specified (direct entry), last registered source will be used. 


Some generators of paid traffic use auto-tags for reference links from advertising campaigns. Google uses GET parameter gclid that is not usually accompanied by supplementary UTM marks.

In such cases, IO system identifies such traffic and tags as follows:

  • source = google
  • medium = cpc


A new session may be initiated by meeting one of the following conditions:

  • once user enters the site from a new referrer,
  • once last session is closed at midnight according to user’s timezone,*
  • after 30 minutes of inactivity (can be set to a custom value).*

 * Further user actions will trigger new session. 

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