Christian Schulze
Associate Professor of Marketing
Frankfurt School of Finance & Management
Christian Schulze is an associate professor of marketing at Frankfurt School of Finance & Management, where he studies customer strategy, e-commerce and digital marketing. With Maximilian Kaiser, he measured how shoppers sent by ChatGPT behaved on 973 online stores, in a study published in Marketing Science in 2026.
Measuring ChatGPT as a Shopping Channel
"Our findings contradict the idea that ChatGPT has already transformed online shopping," Schulze said when Frankfurt School announced the study in June 2026. The paper, ChatGPT Referrals to E-Commerce Websites, written with Maximilian Kaiser, compared organic ChatGPT traffic with organic search, paid search, email, affiliate and paid social across 973 e-commerce sites with more than $20 billion in combined revenue, from August 2024 to July 2025.
A year after ChatGPT added organic shopping links, traffic from LLMs made up less than 0.2% of visits in the sample. ChatGPT referrals converted better and earned more revenue per session than paid social, but trailed every other established channel, although their conversion rates rose over the period. "The real story is in the product categories," Schulze said.
Complex Products Versus Simple Ones
"For simple purchase decisions, its value is currently limited," he said in the Frankfurt School release. "For more complex products, however, ChatGPT can already create value by structuring information, making alternatives comparable and supporting consumers in their decision-making process." His advice was that companies "should therefore assess very carefully whether their products benefit from this type of guidance."
The study's observation window closed before LLM platforms launched instant checkout and agentic shopping, moves the release presented as responses to the gaps in product availability, recommendations and checkout that the study found. The study ranked among SSRN's 250 most downloaded papers of 2025, according to his faculty profile.
From BCG to Frankfurt School
Before academia, Schulze was a consultant at The Boston Consulting Group, advising clients on growth and customer strategy. He earned a PhD in business at Goethe University Frankfurt after graduate study at Technical University Braunschweig and Babson College, was a visiting researcher at the University of Texas at Austin and Boston University, and is a Fulbright Fellow.
His earlier papers covered viral marketing for utilitarian products in the Journal of Marketing, consumer protection on Kickstarter and referral reward size in Marketing Science, and how customer return rates evolve. He teaches Customer Strategy, Digital Marketing and Evidence-Based Management in the school's master's, MBA and Executive MBA programs, and hosts its Customer Strategy Dialogue series with industry leaders.