Solved: Advertising Dual-Sided Marketplace with Google Ads

Hi there,

Thanks for reaching out and explaining the situation with your online marketplace. It sounds like you've hit a pretty common wall when you're trying to serve two completely different sides of a marketplace on advertising platforms, especially somewhere like Google Ads. Happy to give you some initial thoughts and guidance based on what we've seen with similar setups.

You're absolutely right, trying to acquire both expert witnesses and law firms using the same approach on Google Ads is gonna be inefficient at best, and honestly, probably a waste of money at worst. Google's auction system works by matching what someone searches for (keywords) with your ads and how relevant your landing page is. It doesn't magically know if the person typing is a lawyer looking for help or a doctor looking for work.

This is where the fundamental requirement comes in: you need entirely separate advertising campaigns for each audience. Think of them as two distinct businesses you're marketing. One business sells "finding expert witnesses" to law firms, and the other "listing services as an expert witness" to professionals. Everything needs to be segmented along these lines.

The Need for Separate Campaigns and Structure...

On Google Ads, this means you'll have one whole set of campaigns focused purely on attracting law firms. These campaigns would target keywords that law firms would use when they need an expert – phrases like "find medical expert witness", "forensic accounting expert for court", "engineer expert witness testimony", maybe more specific ones like "neurology expert legal case".

The ads within these campaigns need to speak directly to the law firm's pain points: finding the right expert quickly, getting reliable testimony, saving time on sourcing. The ad copy should be tailored to them. When they click the ad, they absolutely MUST land on a page on your website that is all about finding experts – explaining how your platform helps law firms, showcasing the types of experts available, outlining the process for them. Trying to send them to your homepage or a general "about us" page will kill your conversion rate stone dead.

Simultaneously, you need another, completely separate set of campaigns aimed at attracting the expert witnesses themselves. The keywords here will be totally different: "how to become an expert witness", "expert witness jobs", "list expert witness services", "get expert witness cases".

The ads for this audience need to address what *they* care about: finding new opportunities, supplementing their income, how your platform makes it easy to list their services and connect with law firms. Their clicks need to go to a dedicated landing page focused on joining your platform as an expert – explaining the benefits, showing signup steps, maybe featuring testimonials from other experts. If an expert clicks an ad and lands on a page designed for law firms, they're gone.

Trying to put keywords for both audiences in the same campaign, or even in the same ad group, makes it impossible for Google to figure out who you're trying to reach with which message. It also messes up your data – you won't know if the keywords attracting experts are accidentally showing ads meant for lawyers, or vice versa. This guages your results and means you can't optimise effectively because the performance data is mixed up.

Website and Landing Page Importance...

Just having separate campaigns isn't enough though. This brings us to the importance of your website and those specific landing pages. As we see with a lot of clients, especially in B2B or for services, your website is often the biggest blocker if ads aren't performing. You could have teh best campaigns in the world, but if the landing page isn't persuasive and clear, people just won't convert.

For your law firm audience, the landing page needs to build trust that you have high-quality experts available and make it easy for them to search or get in touch. For the expert audience, the page needs to convince them of the value of listing with you and have a clear call to action for signing up or learning more. These pages need to be well-designed, load quickly, and have compelling copy that speaks directly to that specific audience's needs and motivations.

Going back to previous experience, we've seen this time and again. For instance, working with B2B SaaS clients, even with good targeting on LinkedIn or Google Search, if their free trial signup page or demo request page wasn't optimised with persuasive copy and a clear process, the cost per lead stayed high. Making improvements there can dramatically lower acquisition costs because more of the traffic you pay for actually converts into a lead or signup. We often use a copywriter experienced in B2B and SaaS for this, as it's a different beast than B2C copy.

Finding the Right Agency...

Okay, so you've correctly identified that managing this dual-sided, B2B-ish advertising is complex and looking for external help makes sense. You're also spot on that finding an agency that understands this specific dynamic can be tricky. Most agencies are geared towards driving sales of a single product or generating leads for one service.

What you need is an agency with solid B2B experience, first and foremost. Advertising to businesses is just different from advertising to consumers. Sales cycles are usually longer (especially for something potentially complex or expensive like retaining an expert witness), the decision-making process involves multiple people, and conversion events might be leads, demo requests, or signups rather than immediate purchases. You need an agency that gets this and knows how to structure campaigns and offers for a B2B audience.

Look at their case studies. Don't just look at big numbers or huge ROAS figures if they're all from eCommerce or B2C subscription boxes (like our 1000% ROAS for a subscription box or 691% for women's apparel). While those show general advertising skill, they don't show they understand the nuances of B2B or complex service sales. Look for case studies that mention B2B clients, and specifically metrics like cost per lead (CPL), cost per signup, or cost per trial. We've got several like that for SaaS clients, including one where we drove B2B leads for around $22 CPL on LinkedIn, and another software client where we got 4,622 registrations at $2.38 each on Meta.

Crucially, you need to ask them how they would handle advertising for *two* distinct audiences simultaneously within your marketplace model. This is the weird specific question you were thinking of. They should immediately talk about needing completely separate strategies, campaigns, keywords, ads, and landing pages for the expert side and the law firm side. If they don't immediately grasp this distinction and how they'd manage it technically within Google Ads (or other platforms), that's a major red flag. Ask them: "Exactly how would you segment the campaigns in Google Ads to ensure we're showing the right ads to potential law firms vs. potential expert witnesses?" Listen for a detailed answer about campaign structure, ad group themes, keyword types, and the different landing pages they'd require.

You mentioned a medical job matching SaaS – we've actually worked on a campaign for a very similar setup where we were connecting medical professionals with employers. That also required targeting two distinct groups (healthcare workers and hiring managers/practices) on platforms like Meta and Google. We achieved CPA's as low as £7 after optimisation, showing it's definitely possible to make these dual-sided models work with the right strategy and segmentation.

Ultimately, you want an agency that demonstrates a clear understanding of *your specific business model's* advertising challenges, not just general advertising principles. They need to show they can think about the different motivations and search behaviours of each audience and translate that into a concrete, segmented campaign plan.

Actionable Steps to Consider...

Based on all this, here are some initial actionable steps I'd recommend you think about or discuss with any potential agency:

Getting these foundational elements right is absolutly critical before you spend significant money on ads. If the structure isn't right, you'll be fighting an uphill battle, paying too much for clicks, and getting low-quality leads or signups.

Considering Expert Help...

You mentioned you feel way out of your depth doing this yourselves, and that's completely understandable. As you can see, setting up and managing advertising for a dual-sided marketplace, especially in B2B niches, requires a deep understanding of campaign structure, audience segmentation, keyword strategy, landing page optimisation, and ongoing testing. It's a full-time job in itself if you want to do it effectively.

An experienced agency or consultant who has navigated similar complex advertising challenges can save you a significant amount of time, money, and frustration. They already know the pitfalls, have proven strategies for segmentation and optimisation, and can build campaigns designed for efficiency and results from day one. They can also help you interpret the performance data correctly for each side of your marketplace and make informed decisions on where to allocate budget and what to test next.

Getting this right at the start is key to getting your marketplace off the ground successfully with paid advertising. It sounds like you've built a great platform connecting a real need, so getting the customer acquisition piece sorted is the next, vital step.

Happy to chat through this in more detail if you'd find that helpful and offer some more specific thoughts tailored to your situation. We offer a free consultation for just this sort of thing, no pressure at all, just an opportunity to explore your specific challenges and see if our experience aligns with what you need.

Regards,
Team @ Lukas Holschuh