Specialist Marketplace Trap: How Staying in One Category Costs You Growth

Specialist marketplaces are e-commerce platforms that focus on one category type. We recently identified their primary growth lever, which is less about new business and more about expanding existing customer lifetime value.

The data confirms what works: the platforms pulling ahead are those that have expanded their category offering to increase purchase frequency and basket size among existing customers.

Plotting 135 Category Specialists and Their Growth

Mono-category specialists are those with at over 95% of their GMV coming from the main category. Compared to specialists who added adjacent categories to their category mix, the mono-category specialists grew much slower, at 13.3% versus 18.0%.

Adjacent category expansion, which means adding similar categories to the product mix, also correlates with a higher purchase frequency of 3.7 times a year. Platforms that stayed within a single category had a customer purchase frequency of 2.7.

How Zalando Increased Customer Engagement Over Two Years

Zalando began as a fashion retailer. Between 2023 and 2025, it expanded into care products and new categories, reducing fashion's share of GMV from 92% to 87% while adding breadth.

The effect on customer behavior was directly measurable: GMV per buyer rose from US$270 to US$318, and purchase frequency increased from 4.5 to 5.1 orders per year. Customers who had a reason to return more often spent more in total.

Trendyol Improved Client Interactions With a Deepened Focus on Grocery

Trendyol took a different route to the same outcome. Rather than entering a new category altogether, it deepened an existing segment; grocery. From 2023 to 2025, Trendyol grew its grocery offering by 8 percentage points up to 13% of GMV. Fashion's share of the mix declined from 49% to 31% as grocery became a more regular touchpoint.

Consequently, GMV per buyer climbed from US$151 to US$173, and purchase frequency rose from 3.6 to 3.9.

Takeaway: Adding Adjacent Categories as a Specialist Growth Strategy

Two marketplaces, different category bets, same underlying logic. Adding adjacent categories gives existing customers more reasons to return, which compounds over time into higher customer lifetime value. It is a more defensible growth path than relying on continuous new-buyer acquisition, which is costly and subject to diminishing returns.