Third Hemisphere: Marketing for AI
Professional Services
- Marketing for AI
- Content Marketing
- Thought Leadership
Third Hemisphere ran its own Marketing for AI programme on itself, publishing GEO Articles built for the way assistants read and quote. Impressions rose 66 percent to 802,000, average position improved 8.9 places, and traffic from ChatGPT now converts at 7.1 percent, second only to paid search.
The Challenge
Buyers now ask an AI assistant first. ChatGPT, Claude, Gemini, or Perplexity answers in seconds and names two or three companies inside that answer, so the shortlist is set before anyone visits a website or fills in a form. Third Hemisphere was selling a service built on that shift while carrying the same problem as its clients: no deliberate presence in the sources those engines read. An agency asking companies to invest in being citable needs its own numbers first.
Our Strategy
The first page of Google rewards budget and domain authority, and the visibility stops the day the spend stops. Generative engine optimisation works on different mechanics: the assistant picks the passage that best answers the question, whatever the size of the domain behind it. A small site that resolves a narrow question better than anyone else gets cited beside a multinational. Third Hemisphere chose the conversations it wanted to own and set out to answer those questions better than anyone else was answering them.
The Execution
The agency published GEO Articles: 1,500 to 2,500 word pieces written to be read by machines as well as people. Each one opens with a plain-language definition, uses question-based subheads matching how buyers actually ask, and answers each question in a self-contained 40 to 90 word passage an assistant can quote whole. Every statistic links to a primary source, and every piece links back to a relevant Third Hemisphere page. The articles run in the Insights section, with further pieces placed on Medium and other sites language models read easily, each built around a term the agency wants to own.
The Results
Comparing 1 April to 27 July 2026 against the same window in 2025, total search impressions rose from 482,000 to 802,000, a 66 percent increase, and average position improved from 28.5 to 19.6, a gain of 8.9 places. Traffic arriving from ChatGPT converts at 7.1 percent, second only to paid search at 7.8 percent, and ahead of organic search, direct, social, and email. Most brands are yet to appear consistently in AI citations, so the cost of moving early is still low.
- 66% growth in search impressions
- 8.9 places gained in average position
- 7.1% conversion rate from ChatGPT traffic