Six core concepts of Optimizely Web Personalization

  • Updated
This topic describes how to:
  • Learn about the six core concepts behind Optimizely Web Personalization
  • Understand pages, tags, and events

Optimizely Web Personalization helps you deliver targeted experiences to different visitors to your site based on behaviors, in real time.

This topic explains several concepts that work together to help you deliver targeted experiences to visitors -- and measure the impact. Use it to learn how a personalization campaign works.

See Inspiration for Personalization to get started.

When you are ready to implement your site for Optimizely Web Personalization, see setting up the components, which you will use to build campaigns.


Pages are sections of your site where you modify the experience and track behavior.

Examples: Homepage, Product Detail page, Article page, Checkout page, Confirmation page, Navigation menu

Set up pages for all the meaningful places where you deliver custom messaging or experiences on your site. Later, you’ll use these pages to quickly build impactful experiences and capture your visitors’ behavior.

A page can be:

  • single URL where you want to change the experience (like your homepage)

  • pattern of URLs that all share the same template (like all the product detail pages on an e-commerce site)

  • Or a global URL that targets all URLs with the snippet to change elements that appear across pages (such as a navigation menu). 

Here are the main ways to use pages:

  • When you create a campaign, you’ll choose one or more pages where you'll deliver the experience.

  • When a visitor lands on a page, Optimizely automatically tracks a pageview event. You can use this event for behavioral targeting. For example, you might personalize an experience for visitors who've viewed the checkout page. Or, you can use views on a page to measure success in a campaign: did the new experience increase views to the checkout page?

  • On each page, you can create events and tags to track visitor behavior: for example, to understand what products visitors are buying.

If you use Optimizely to test on a checkout page, you might need to configure your site for PCI compliance.

Pages are always-on. This allows you to constantly gather information about customer behavior on your site, using events and tags, regardless of whether a campaign is running.

Events and metrics

Events track key visitor behaviors on your site, such as clicks, pageviews, and form submissions.

Examples: Add to Cart, Save to Wishlist, Share, Search, Click Promotion

When you create a page, you can track whether customers click a button or watch a certain video, for example. Use events to measure success in an A/B test or deliver behaviorally targeted experiences. 

A metric is when you add events to a campaign to measure success.

You can track these kinds of behaviors with events:

  • Click events. Capture user clicks on elements like buttons or offers. You create these on a page, and they inherit the URL targeting from that page.

  • Pageview events. Tracked automatically for each page that you set up.

  • Custom events. Capture additional information using custom code. You can use these to track behaviors like watching a video, submitting a form, or other actions that aren’t always reflected in clicks.

When you set up an event, Optimizely tracks it for any visitor to the site.

Events are always-on. This means that they constantly gather information on the behaviors that you identified, regardless of whether you’ve created or connected any campaigns to those events.

Always-on event tracking lets you:

  • Create audiences based on behavior. You can target visitors who triggered a certain event over some time period (“People who searched 2+ times in the last 30 days”), or get more specific with Tags.

  • Measure results for your campaigns.


Tags capture information that appears on the pages of your website. Tags describe parts of a page that visitors engage with, such as the type of product and what it costs.

Examples: Price, Category, Name, Quantity, Duration

Together, tags and events provide data-rich picture of your visitors’ behavior.

For example, you may know from your events that a customer clicked the Add-to-Cart button. But what did they add to the cart?

If you add tags to the product name and the price tag on that page, you also know that this customer added blue shoes that cost $115. When you create a personalization campaign, you can target “Customers who added blue shoes to their cart” or “Customers who spent more than $100.” Tags let you capture this extra context and use it for behavioral targeting.

Tags are always-on. This means that they constantly gather information on visitor behaviors, regardless of whether you’ve connected any campaigns to those tags.


Audiences are groups of customers to whom you’ll deliver a targeted experience. Conceptually, an audience is simply a group of visitors who have something in common.

In Optimizely Web Personalization, you can create audiences based on behavior. So, you'll be able to behaviorally target audiences made up of visitors who've behaved in a certain way. For instance, you might create an audience for customers who've browsed a certain product or have seen a promotional campaign.

When you setup the pages, events, and tags on your site, you can create behaviorally targeted audiences. For example: 

  • “Heavy Spenders”: people who triggered the event Add to Cart at least once in the last 30 days where price > $200

  • “Shoe Shoppers”: people who viewed a Product Detail Page at least twice in the last 60 days where category = “Shoes”

  • “Abandoned Cart”: people who triggered Add to Cart at least once but did not Purchase

Learn to set up behaviorally targeted audiences.


Use the Editor to create experiences for visitors, based on the page they visit and the audiences they qualify for. Use these experiences to test and personalize your site.

In Web Personalization, a campaign contains several experiences that are assigned to visitors based on the audiences they qualify for, such as personalizing a landing page with two experiences: showing a female model to the "Women" audience and a male model to the "Men" audience.

You can create experiences in Web Personalization by making changes with the Visual Editor or with custom code.

Personalization campaigns

In Optimizely Web Personalization, campaigns are the framework that organize your personalization strategy. A campaign takes a piece of your site, like the promotions on your homepage, and swaps out that content for different audiences.

For example, a single Homepage Offers campaign might show dress deals to "Dress Shoppers," shoe deals to "Shoe shoppers," and hat deals to "Hat Shoppers." Within a campaign, you'll create sets of experiences for visitors who are bucketed into an audience on a certain page.

Create a new campaign for each section of the site you want to personalize.

Examples: Homepage Offers campaign, Email signup CTA campaign, Top Banner campaign, Checkout Cross-sell campaign

When you create a new campaign, set up a few key pieces:

  • Name
    Name your campaign based on what you are personalizing, or the core principle behind your personalization strategy. For example, you might name a campaign Promotional Hero Banner or Video View Offer. You may be tempted to name your campaign based on “who” you’re personalizing to, but remember that a single campaign can deliver multiple experiences to different audiences.

  • Pages
    Decide where your campaign runs by choosing one or more of the pages you already defined. Or, create a new page. You can run multiple campaigns on a single page. For example, you might have one campaign that personalizes the hero image at the top and another that personalizes the email signup form at the bottom. A single campaign can also span multiple pages to create seamless messaging across a checkout funnel.

  • Audiences
    Decide who sees your campaign by selecting one or more of the audiences you already defined. Or, create a new audience. In the Editor, create a unique experience for each audience on each page. If a visitor falls into multiple audience, they only see one experience. You can decide which experience “wins” by prioritizing your audiences in a particular order. Visitors will see the highest-priority experience they qualify for.

  • Primary metric
    Every event that you set up in Optimizely Web is tracked all the time. You do not need to attach specific goals to each campaign that you run. However, you can choose one event as the primary metric for a campaign. This metric shows at the top of the Results page.

  • Holdback
    Every campaign has a “holdback,” which is like the control of an A/B test. By default, Personalization shows 95% of visitors in a campaign a personalized experience, and holds back 5% who see the original.

    You can make the holdback larger to get data faster, or shrink it if you are very confident. You should use 5% so you can monitor how well your personalization is doing. Changing your holdback mid-campaign is not currently supported by our Stats Engine. If you choose to do this, you may see statistical reports which are invalid.

    The following image shows how to set a holdback.

When you created personalized experiences for your audiences, launch your campaign by publishing it. When you publish a campaign, you make your changes live to the world. If you make more changes after you publish, they are saved in “draft” mode but do not go live until you publish again.

How Web Personalization works 

The first step to using Web Personalization is teaching Optimizely about your site. When you set up the key pages, events, and tags on your site, you help Optimizely develop a data-rich picture of your visitors’ behavior. Use these behaviors alongside data from other resources to create audiences.

When you defined the audiences you want to personalize for and the pages where you deliver that messaging, you create a campaign. A campaign lets you deliver personalized experiences to different audiences on each page.

When you run a campaign, measure how effective it is. The Web Personalization Results page uses a holdback to measure the lift of your primary metric and any other events you’ve tracked. You can view these results for a whole campaign or by audience.