Growth Intelligence Brief #8

Bing's mysterious growth, AI Mode as default, the first-ever AI Mode usability study, Nerdwallet down / Reddit up / online retailers down

Sep 24, 2025

∙ Paid

Welcome to another Growth Intelligence Brief, where organic growth leaders discover what matters - getting insights into the bigger picture and guidance on how to stay ahead of the competition.

As a free subscriber, you’re getting the first big story. Premium subscribers get the whole brief.

Today’s Growth Intelligence Brief went out to 437 marketing leaders.

This week, we’re looking at new AI search experience and their impact on the ecosystem:

Bing is growing for mysterious reasons
AI Mode is on track to become the default search experience
The first-ever AI Mode usability study

I’ll also connect the dots on what this all means for you.

What’s going on with Bing?

Here’s what happened:

Bing has grown ~20% from January to July in 2025, mostly direct traffic in the US.

The data comes from Similarweb, which uses clickstream to track user behavior. So, the increase isn’t caused by (LLM) crawlers.

Therefore, it must be real user data.

Why this news matters:

Bing said before that their search market share went up:

According to Comscore, Bing now has 29 percent of US search share, compared to around 60 percent for Google. That’s a 2.1 percentage point increase since the launch of Bing Chat in February 2023.

Based on StatCounter, Google stands at ~85.7% market share in the US in August 2025, compared to 87.3% in August 2020.

Bing, on the other hand, went from 7.2% to 7.9% in the same time period.

My take on this:

There has been a lot of chatter around ChatGPT using Google for answers that require web searches. I wouldn’t give too much weight to that.

In my observation, Bing indexing is still critical for being visible in ChatGPT, which is by far the most used LLM.

Also, ChatGPT doesn’t scrape Google directly but uses SERPapi for the data.

Here’s what to do:

Check your referral traffic data for Bing over the last 12 months.
Compare how your site is indexed in Google (Search Console) vs. Bing (Webmaster Tools).
If you see problems, use the IndexNow API by Bing.