What You’ll Learn

Google Business Profile categories control which local searches your business appears in. Most businesses set their primary category and never touch secondary categories — leaving visibility on the table. Your top-ranking competitors have probably figured out which secondary categories expand their reach. The GMBB Spy extension surfaces exactly what they’re using. This guide shows you how.

Key Takeaways

• Secondary GBP categories expand which searches you appear in beyond your primary category.
• GMBB Spy is a free Chrome extension that reveals the categories (primary and secondary) of any GBP listing.
• Only add secondary categories that genuinely apply to your business. Irrelevant categories can hurt relevance.
• Takes 10 minutes. Free. No SEO expertise needed.

Why Secondary Categories Matter

Your primary GBP category is what Google uses to decide the main searches you’re relevant for. A plumber with “Plumber” as primary shows up for “plumber near me” searches.

Secondary categories expand that. A plumber who also adds “Water heater repair service” and “Drain cleaning service” as secondaries now appears in those searches too — without needing separate listings or pages.

The businesses ranking above you have likely done this analysis. You can see exactly what they chose in about two minutes.

Step 1: Install GMBB Spy

Search “GMBB Spy” in the Chrome Web Store and install the free extension. No account required.

Step 2: Find Your Top Competitors on Google Maps

Search your main service plus your city on Google Maps: “electrician Austin” or “roof repair Phoenix”.

Identify the 2–3 businesses consistently ranking in the top 3 results. These are the profiles you want to analyze.

Step 3: View Their Categories

Click on a competitor’s listing to open their GBP. With GMBB Spy active, you’ll see their full category list — primary and all secondaries — displayed on the listing.

Note every secondary category they use. Do this for 2–3 competitors. You’ll start to see patterns: categories multiple high-ranking competitors share are almost certainly contributing to their visibility.

Step 4: Add Relevant Categories to Your GBP

Log into your Google Business Profile. Go to Edit Profile → Business category → Add another category.

Add the secondary categories from your competitor research that genuinely apply to your business. If you’re a plumber who also does water heater installations, “Water heater repair service” is legitimate. If you don’t do that service, don’t add it — mismatched categories confuse potential customers and can hurt your overall relevance score.

Don’t try to add every category your competitors use. Only add the ones that accurately describe what you actually do.

How Often to Review

Set a quarterly reminder to re-check your top competitors’ categories. Businesses update their profiles, and new category options become available as Google expands its category library.

Actionable Checklist

• Install GMBB Spy from the Chrome Web Store.
• Search your service + city on Google Maps. Identify top 2–3 competitors.
• Use GMBB Spy to view their secondary categories. Note the ones multiple competitors share.
• Log into your GBP. Add secondary categories that accurately reflect your actual services.
• Set a quarterly reminder to repeat the competitor category audit.

Wrap-Up

Ten minutes, a free browser extension, and your top competitors show you exactly which searches they’re capturing that you’re not. Add the relevant categories, and your profile starts appearing in those same searches. It’s one of the fastest GBP improvements available — and it’s completely free.