User data

Sending user data enables accurate matching of conversions and retargeting audiences even in cookieless environments – for example on mobile devices or in browsers that block third-party tracking.

Why send user data?

The key identifier is the user’s e-mail (em). If you know it (logged-in customer, completed order), SEM will link the event to a specific user even without a cookie present. This increases conversion attribution accuracy and the quality of retargeting audiences across devices.

Other parameters (phone, name, address, gender…) are optional. They can be used as conditions when creating retargeting and conversion lists – for example targeting only customers from a specific city or filtering by gender.

When to send user data?

• After user login – call updateUserData immediately after login
• After order completion – in the Purchase event together with order data
• Whenever data is available – for example on page load when you know the customer is logged in

User data parameters

All values are of type string. In a frontend implementation send them in plain text – the script handles hashing.

The updateUserData method

Send user data using SEM('updateUserData', userData). Call it whenever data is available – ideally immediately after user login or on page load when you know the customer is logged in.

const userData = {
  em: "jan.novak@email.cz",   // hashed automatically
  ph: "+420606666666",
  fn: "Jan",
  ln: "Novák",
  ge: "m",
  db: "19870223",
  ct: "Praha",
  zp: "14900",
  sr: "Ulice 12",
  country: "cz"
};

SEM('updateUserData', userData);

If you are only sending an e-mail, a minimal variant is sufficient:

SEM('updateUserData', { em: "jan.novak@email.cz" });

Sending together with an event

User data can be set once using updateUserData and then events sent normally – the data will be attached automatically. Alternatively it can be passed directly in the event body. Both approaches are equivalent.

// Call immediately after the user logs in
if (isLoggedIn) {
  SEM('updateUserData', {
    em: currentUser.email
  });
}

// Subsequent events are automatically linked to this user
SEM('track', 'ViewContent', { /* ... */ });

S2S measurement – hash yourself

With Server-to-Server measurement you must hash personal data using SHA-256 on your own server before sending to Sklik. The result is a 64-character hexadecimal string.

Node.js

const crypto = require('crypto');

function hashValue(value) {
  return crypto
    .createHash('sha256')
    .update(value.trim().toLowerCase())
    .digest('hex');
}

const userData = {
  em: hashValue('jan.novak@email.cz'),
  ph: hashValue('+420606666666'),
  fn: hashValue('jan'),
  ln: hashValue('novák'),
};

PHP

function hashValue($value) {
    return hash('sha256', strtolower(trim($value)));
}

$userData = [
    'em' => hashValue('jan.novak@email.cz'),
    'ph' => hashValue('+420606666666'),
    'fn' => hashValue('jan'),
    'ln' => hashValue('novák'),
];

Python

import hashlib

def hash_value(value):
    return hashlib.sha256(value.strip().lower().encode()).hexdigest()

user_data = {
    'em': hash_value('jan.novak@email.cz'),
    'ph': hash_value('+420606666666'),
    'fn': hash_value('jan'),
    'ln': hash_value('novak'),
}

Use in retargeting and conversions

Geographic and demographic parameters (ct, region, ge…) can be used as conditions when creating retargeting lists and conversions in the Event Management section. For example:

• Retargeting list only for customers from Prague → condition ct = Praha
• Conversions only for women → condition ge = f
• Combined: customers from Brno who viewed the “Televize” category

Conditions within a single event are evaluated against objects in the contents array – a combination of parameters always applies within one object (AND logic inside an object, OR logic across objects). See the Dynamic retargeting section for more.