Imagine running a physical store where everyone shops in the dark. You can hear the cash register ring occasionally, but you have no idea who came in, which aisles they walked down, or why 50 people walked in the door and immediately turned around and left. That is running a website without Web Analytics.

Web Analytics is the measurement, collection, analysis, and reporting of web data to understand and optimize web usage. Historically, this meant counting “Hits” or “Pageviews.” In 2025, it has evolved into a complex science of tracking User Behavior (Events) across devices.

While Amplitude (a product analytics tool) argues that traditional web analytics is dead, the reality is that you need to understand both the “Traffic” (Who came?) and the “Behavior” (What did they do?).

How It Works (The Technical Bit)

Web Analytics relies on a tiny piece of code called a Snippet (usually JavaScript) placed on every page of your website.

1. The Visit: A user lands on your site.

2. The Trigger: The browser executes the snippet (e.g., the Google Tag).

3. The Cookie: The site drops a “Cookie” on the user’s browser to assign them a unique ID. This allows the system to know if “User 123” is the same person who visited yesterday.

4. The Ping: The browser sends data back to the Analytics Server (Google, Adobe, Amplitude) saying: “User 123 viewed the Home Page at 10:00 AM from an iPhone in London.”

The Big Shift: Sessions vs. Events

To understand modern analytics (like GA4), you must understand the shift from Sessions to Events.

The Old Way: Session-Based (Universal Analytics)

• Focus: Time.

• Logic: A “Session” is a bucket of time (usually 30 minutes). If a user visits, reads three pages, and leaves, that is “1 Session.”

• The Metric: Bounce Rate. (Did they leave without clicking a second page?)

• The Problem: It is passive. If a user spends 20 minutes reading a single blog post and then leaves, the old logic called that a “Bounce” (Failure).

The New Way: Event-Based (GA4 & Amplitude)

• Focus: Action.

• Logic: Instead of just “viewing pages,” every action is an “Event.” Scrolling 90% down the page is an event. Watching a video is an event. Clicking a button is an event.

• The Metric: Engagement Rate.

• The Solution: Now, that user who read your blog for 20 minutes isn’t a “Bounce”; they are an “Engaged User” because they triggered the “Scroll” event.

Marketing Analytics vs. Product Analytics

This is where many businesses get confused. Do you need Google Analytics or Amplitude?

Marketing Analytics (e.g., Google Analytics 4)

• The Question: “Where did they come from?”

• Focus: Acquisition and Traffic.

• Key Metrics: Traffic Sources, Landing Pages, Campaign ROI.

• Best For: Marketing teams trying to optimize ad spend and SEO.

Product Analytics (e.g., Amplitude, Mixpanel)

• The Question: “What did they do after they logged in?”

• Focus: Retention and Feature Usage.

• Key Metrics: Churn, Daily Active Users (DAU), Stickiness.

• Best For: Product Managers trying to build a better app.

The Verdict: Most modern digital businesses need both. You need GA4 to see how you got the user, and Amplitude to see if they liked the product.

The Metrics You Actually Need to Watch

Ignore the vanity metrics. These are the ones that matter in 2025.

1. Users (New vs. Returning): Are you growing (New) or building loyalty (Returning)?

2. Engagement Rate: The percentage of sessions that lasted longer than 10 seconds or had a conversion. This replaces the outdated “Bounce Rate.”

3. Events per User: How active are they? A user who triggers 20 events is more valuable than one who triggers 2.

4. Attribution Source: Did this user come from TikTok, Google, or an Email?

The Privacy Challenge

Web Analytics is facing its biggest threat: Privacy. With GDPR in Europe and the death of Third-Party Cookies, analytics tools are becoming “blind” to certain data.

• Modeling: Tools like GA4 now use AI to “fill in the gaps” when users opt out of tracking.

• Server-Side Tracking: Advanced marketers are moving tracking from the browser (client-side) to the server to bypass ad blockers.

Conclusion

Web Analytics is the dashboard of your business. Without it, you are making decisions based on feelings rather than facts. Whether you are looking at simple traffic logs or complex event funnels, the goal remains the same: turn data into insights, and insights into action.