A/B Testing

A/B testing lets you measure the impact of switching to Marqo by running it side by side with your existing search implementation. You split storefront traffic between two variants - control (your current search) and marqo (Marqo search) - and compare engagement, conversion, and revenue metrics in the Analytics dashboard.

How It Works

1. Assign variants: When a user visits your storefront, they are assigned to a variant of the experiment, either control or marqo. The assignment is sticky: the same user gets the same variant on every page load and return visit.
2. Route search requests: For control users, send queries to your existing search backend as normal. For marqo users, send queries to Marqo.
3. Compare results: The Pixel tags all events (searches, clicks, add-to-carts, purchases) with the variant. Use the Analytics dashboard to compare metrics and determine which backend delivers better outcomes.

Setup

Prerequisites

• The Event Tracking Pixel is installed on and configured for your storefront.
• Your Marqo index is set up, configured, and serving search results.

Step 1: Assign Users to Variants

The Pixel provides a built-in method that divides users into equal buckets using the most persistent identifier available (user ID > session ID > IP address, falling back to a random assignment). Call it early in your page lifecycle, right after the Pixel loads:

const variant = window.MARQO_PIXEL.chooseVariant(["control", "marqo"]);

This returns "control" or "marqo". The assignment is deterministic: the same user gets the same variant on every page load and return visit, with no extra storage logic needed on your side.

The Pixel automatically tags all subsequent events with the chosen variant.

Step 2: Route Search Requests

Use the variant to decide which search backend handles each request:

const variant = window.MARQO_PIXEL.chooseVariant(["control", "marqo"]);

async function search(query) {
  if (variant === "marqo") {
    // Send the query to Marqo
    const response = await fetch(
      `https://ecom.marqo-ep.ai/api/v1/search?q=${encodeURIComponent(query)}`,
      { headers: { "x-marqo-index-id": `${indexId}` } }
    );
    return response.json();
  }

  // Default: send the query to your existing search backend
  return existingSearch(query);
}

Step 3: Compare Results

The Analytics API and Analytics dashboard break down all metrics by variant. Compare key indicators between control and marqo:

Metric	What it tells you
Click-through rate	Are users finding results more relevant?
Add-to-cart rate	Are results driving stronger purchase intent?
Conversion rate	Are more sessions ending in a purchase?
Revenue per session	Is overall revenue increasing?

Best Practices

• Make sure both variants use the Pixel: the Pixel must be loaded for all users, including the control group, so you have complete data for comparison.
• Avoid other changes during the test: don't redesign the results page or change merchandising rules mid-test, as this makes it harder to attribute differences to the search backend.

Using Your Own A/B Testing Tools

If you already have your own A/B testing or analytics tools in place, discuss with your Marqo account manager to help you integrate them with Marqo and ensure everything works smoothly.