Both firms use the same three letters. They don't do the same job. Here's what each says about itself, in its own words, and the questions that actually separate them for a buyer.
Houses of Growth describes itself as a founder-led agency that helps B2B SaaS companies generate revenue from AI search. Its stated target client is a SaaS company that's invisible in Google and AI answers, or unhappy with a previous agency or freelancer.
Its model runs three lines: AI Search & SEO (long-form content, brand mentions placed on third-party publishers, on-page optimization, Google Business Profile work), Reddit Marketing (signal-based posts in high-intent communities), and Paid Search (landing pages, Google Ads, with a stated plan to add ChatGPT Ads). It publishes named case-study metrics - a 33% pipeline share from AEO for one client, 100k monthly organic traffic for another, a six-figure enterprise deal attributed to AI search engines for a third. For measurement it uses a third-party AI-visibility tracking tool rather than a proprietary instrument, and reports results as case narratives rather than a published methodology.
Index Lab describes itself as an "AI-SEO-native" agency with the tagline "Be the brand AI recommends," operating from Lisbon, Dubai and London. Its framing: traditional SEO chases ranked blue links, while its work targets visibility inside the AI answer itself.
Its stated framework has seven parts: prompt and content strategy, an AI visibility audit, AI-ready site optimization, content execution, information-source pages, source hunting, and ongoing monitoring. Clients can buy the full framework or individual pieces. It names ChatGPT, Google Gemini and Google AI as target platforms, offers two free diagnostic scans (an "LLM Visibility Scan" and an "LLM Readiness Audit") as an entry point, and lists a client portfolio including Wandr, Flash Facial, Baby Sisters and AlignEat.
Put the same questions to both firms before you sign anything. They're the ones we tell every buyer to ask any AEO provider in our Dubai buyer's guide, adapted here to a direct head-to-head.
Don't compare decks. Ask both firms for the same small, scoped diagnostic against the same 10-15 real buyer questions in your category, priced and timeboxed the same way. Then compare what actually lands in your inbox: the verbatim AI answers, the source list, and the written recommendation, not the pitch.
The firm that hands you re-derivable evidence, is specific about which engines and questions it covers, and tells you plainly what it doesn't measure is easier to judge on its merits than one that hands you a summary slide.
If you need content volume and demand capture across search and Reddit for a SaaS product, Houses of Growth's model is built for that. If you want a structured, AI-specific framework spanning audit through monitoring across ChatGPT and Gemini, Index Lab's model is built for that. Neither firm's public materials describe a frozen, client-approved measurement instrument re-run on a fixed cadence with per-query evidence - that's a different job, and it's worth knowing which one you're actually buying before you sign.
28 Labs is the measurement-first option in this same market. We don't run a SaaS content program and we don't sell a modular AI-SEO framework. We measure a fixed set of real buyer questions across ChatGPT, Claude, Gemini and Perplexity on a repeat cadence, show the verbatim answers, and name what the numbers can and can't prove. If the seven questions above are the ones that matter to your decision, that's our lane, and the same questions apply to us. Start with what a proper diagnostic actually costs: see our AI visibility audit cost guide.