4thline.ai

Growth marketing for established B2C and B2B companies

Marketing that turns search, AI, and ads into revenue.

For home service companies, ecommerce brands, professional firms, and manufacturers ready to grow. One senior team runs your SEO, AI search, paid ads, website, and lead follow-up, and reports on the numbers that matter: leads, calls, cost per lead, and for ecommerce, sales and return on ad spend.

  • 40+ brands served
  • Month-to-month, no contracts
  • You own your ad accounts

Businesses we've worked with

Executive office with a tablet showing growth results

Your buyers are deciding before they ever call.

Homeowners, shoppers, and procurement teams now research on Google, ChatGPT, and other AI tools long before they reach out. If you're not the business they find and trust, the deal goes to a competitor.

We make sure you're the one they find, and that every visit, call, and form turns into a real sales conversation.

See if AI recommends your business

Who we help

We work with growth-minded companies selling to consumers or to other businesses.

B2C Selling to consumers

Newly renovated upscale home exterior

Home services

Roofing, exteriors, HVAC, remodeling, and other high-ticket home service companies. More booked jobs in your service area, plus identified homeowner leads.

Packed orders in a modern brand studio

Ecommerce and consumer brands

DTC and online retail brands scaling profitable sales through search, shopping ads, and social.

B2B Selling to businesses

Machined part beside a robotic manufacturing cell

Manufacturing and industrial

Manufacturers, fabricators, and distributors winning RFQs from engineers and buyers who search before they call.

Modern conference room overlooking the city

Professional services

Law, accounting, financial, medical, and consulting firms that need to be the trusted, recommended name.

Real results from real clients

A few recent numbers. Full breakdowns are on our Results page.

470leads from Meta Ads for a home service company, with cost per lead down 28%
~8xreturn on ad spend for an ecommerce brand, with orders averaging about $200
116page-one Google keywords for a contract manufacturer, 59 of them in the #1 spot

How it works

  1. Strategy call

    We review your site, search presence, and ads, and tell you honestly where the biggest growth is.

  2. We build and launch

    Search, ads, website, and follow-up go live together on a clear timeline.

  3. You see the results

    Clear monthly reporting on leads, calls, cost per lead, rankings, and online sales. We optimize every week.

Does AI recommend your business?

Run a free check of your website across ChatGPT, Gemini, Perplexity, Grok, and Google. Learn more about AI search optimization.

Senior strategy, without the big-agency layers

4th Line Marketing is led by founder Kevin Entmaa. You work directly with the people who build and run your campaigns, not a rotating cast of junior account managers.

More about us

"We report on what we can actually measure: leads, calls, cost per lead, search visibility, and for ecommerce, sales and return on ad spend. If a channel isn't working, we'll tell you."

Kevin Entmaa, Founder

Ready to see what your marketing is really producing?

Book a Strategy Call Get My Free AI Snapshot