Two Agencies, One Sale: How to Split SEO and PPC Without Paying Twice for the Same Customer

Your SEO agency just reported a record month. So did your PPC agency. Add up the revenue each one claims and you get a number bigger than what you actually sold.

Nobody lied. Each agency is reading its own scoreboard, and both scoreboards counted the same customer. That's the hidden cost of splitting SEO and PPC between two agencies: you can end up paying twice for one sale, and nobody can tell you which half of the spend did the work.

Plenty of $10M+ companies run two agencies on purpose. Each one is a specialist, and it can work well. Almost every article on this topic is written by an agency telling you to hire one firm for both. This is the other guide: how to make a two-agency setup work, the rules that keep it honest, and how to know when consolidating actually makes sense.

Where a Two-Agency Split Breaks

The split itself is rarely the problem. The problems come from four predictable gaps between the agencies.

How Much Overlap Is There, Really?

The honest answer: it depends on where you rank, and it's worth measuring for your own business.

Google's own research gives a starting point. Its 2012 study of 390 search ad pause experiments found that when a company already held the top organic result, only half of its ad clicks were incremental. The other half would have arrived through the free listing anyway.

Two caveats matter. These studies are more than a decade old, they measured clicks instead of sales, and Google sells the ads. An independent NBER field experiment at eBay found something harsher for a very well-known brand: "brand-keyword ads have no measurable short-term benefits." Your business probably sits somewhere in between. The point is that overlap is real, it's biggest on your brand name and your best rankings, and neither agency's report will show it to you on its own.

The Rules of Engagement

Two agencies can work well together when a few rules are set early and written down. Here are the ones we'd put in place.

How to Settle the Credit Fight

When both agencies claim the same sales, don't referee the argument. Run a test.

Start with the overlap report. Link Google Search Console to Google Ads and use the paid and organic report to see where your ads and organic listings show up for the same searches. That's where the overlap lives.

Then test the expensive overlap. Pick a set of searches where you already rank near the top, usually your brand name, and pause or reduce the ads there for a few weeks in some regions while keeping them on in others. Measure total leads and revenue in your CRM over the same weeks. For larger accounts, Google offers Conversion Lift, which it describes as "an incrementality tool," through your Google account representative.

Decide with the result. If total qualified leads hold steady with the ads off, that spend was buying sales you'd already won. Move it to non-brand searches where you don't rank yet. If leads drop, the ads were earning their keep, and now you can prove it.

When One Agency Makes More Sense

Consolidating is the better answer in a few situations: when neither agency will share data, when your budget is too small to justify two management fees, or when you keep paying for the same customer twice and the rules above never stick.

The upside of running both under one roof is that paid search and SEO can feed each other on purpose. With Everything But Stromboli, the team behind BulkMemoryCards.com, we focused first on PPC so we knew which keywords would convert. Paid search reached a 6,531.8% return on ad spend, and the SEO built on those proven keywords grew to $24,782 in monthly revenue from free traffic.

That's the same principle a two-agency setup can follow with good rules. One agency simply removes the coordination cost. If you're weighing that, here's how we approach SEO and how we run paid search.

Score Your Two-Agency Setup