Seznam Event Measurement (SEM)
SEM (Seznam Event Measurement) is currently available within the web interface, where you can set up events, configure and test measurements. However, the actual activation of measurement is not yet possible – this feature will be gradually rolled out during June 2026.
A new event measurement system replacing the legacy retargeting and conversion codes. SEM unifies data collection for campaigns, retargeting and optimization in a single script.
What is SEM and why migrate?
SEM (Seznam Event Measurement) is a modern event measurement system for your website that replaces the existing retargeting codes and conversion tracking scripts for both Sklik and Seznam Shopping. Instead of multiple separate scripts, a single SEM script sul.js is all you need.
SEM collects data about user behaviour (product views, add-to-cart actions, purchases, etc.) and sends it to the Seznam ecosystem, where you can use it for:
- Conversion tracking – find out which campaigns drive orders, registrations or leads
- Retargeting – reach users who visited specific pages, products or categories, or who met the event conditions defined in Event Management
- Dynamic retargeting (DRTG) – automatically show ads for the exact products a user browsed
- Campaign optimisation – the system uses collected data for smarter targeting
- Customer reviews – order data enables sending satisfaction surveys and displaying reviews in relevant contexts
What changes after migration?
| Feature | Legacy tracking rc.js | SEM tracking sul.js |
|---|---|---|
| Number of scripts | One conversion type per conversion code | One SEM script for all events |
| Conversions | Jeden typ konverze na konverzní kód | Multiple conversion and micro-conversion event types, detailed reporting, Maximise Conversions for a selected conversion |
| Retargeting lists | Manual setup in the Retargeting tab | Event Management – automatically created per conversion, advanced event-definition options |
| Retargeting conditions | Limited options | URL, category, purchase value, product ID, city, gender, add-to-cart… |
| Consent | Custom solution | Automatically via IAB TCF or Google Consent Mode |
| Seznam Shopping conversion tracking | Requires linking front-end and back-end codes | Full data transfer handled by the SEM front-end script and event parameters |
| Server-to-Server | Not supported | Fully supported (endpoint sem.seznam.cz) |