Sestimi: Revenue up 350% in 30 days with Merchantee

Sestimi.pl is a Polish fashion retailer that has built its commercial strategy around online marketplaces. Across multiple European platforms and markets, Sestimi sells from a catalogue of tens of thousands of products.

The scale brings real opportunity. It also brings a management problem that gets heavier with every product added, every market entered, and every campaign season that arrives.

Sestimi's pricing rules, discount minimums, and advertising limits were clearly defined. There was no confusion about what the strategy should be.

The issue was throughput. On any given day, staying competitive across tens of thousands of products and multiple platforms meant reacting to competitor price changes, evaluating which campaigns made sense to join, directing ad budgets toward the right SKUs, and confirming that every decision still sat within margin and Cost of Sales targets.

That is a significant number of decisions. At Sestimi's scale, it becomes an impossible number to make manually and get right consistently.

Before Merchantee, Sestimi used integration platforms. They handled listings, order flows, and the technical operations of selling across marketplaces. For that purpose, they worked.

But integration tools process instructions. They do not generate them. Deciding which products to enter into an upcoming Allegro Days campaign, checking whether each one clears the margin floor, and doing it across seven markets within the available window, that was never what those platforms were built for.

As the catalogue and market footprint grew, so did the gap between strategy and execution. Not because the direction was unclear, but because there was no capacity to run it at this volume.

Merchantee took on the daily decision load. Sestimi kept the controls.

Sestimi deployed Merchantee as an agentic marketplace expert that continuously evaluates commercial conditions and acts within rules Sestimi defines.

Before any campaign or pricing action, Sestimi set the limits. Pricing floors. Minimum prices for campaign participation. Cost of Sales thresholds. Rules governing how different product categories should behave across different markets. The strategy stayed exactly where it had always been, with Sestimi. The daily work of applying it moved to Merchantee.

Campaign participation, handled automatically.

For every discount campaign across Allegro and Kaufland, Sestimi specified the lowest price at which each product could enter. Merchantee handled the rest: checking available campaigns daily across all markets, comparing eligibility against current prices and predefined rules, and making the call on whether each product should be included or held back. No one at Sestimi had to manage it by hand.

Between October and December 2025, that process covered more than 300,000 offers across 22 campaigns in 7 markets. Products that cleared the rules were entered. Anything that would have broken the margin strategy was blocked. The campaign windows closed. The decisions were already made.

Dynamic pricing that added to the bottom line.

Merchantee tracked competitor prices several times an hour and updated inputs throughout the day. Within Sestimi's defined limits, it made real-time pricing calls: hold the current price, go lower to improve Buy Box probability, or push higher where margin room existed.

Around 13% of all orders were affected by dynamic pricing. Approximately 2% of total revenue came back as pure additional margin, generated entirely by price increases where the market allowed, with no effect on sales volume.

Spend going to products that earned it.

Every day, Merchantee assessed performance across the full catalogue and placed each product into one of three groups.

Superstars: Strong conversion rates. Budget allocated, campaigns active.

Contenders: High click and basket-add activity, low purchase rates. Removing these produced immediate savings with no revenue impact. For each product, Merchantee flagged the specific issue: a format change needed, a first batch of reviews missing, a promotional nudge that could shift the conversion rate.

Cold Stocks: Minimal interaction. Held back from ad spend until listing fundamentals like title, lead image, and subcategory were reviewed first.

Budgets stopped funding underperformers and concentrated where conversion justified it.

‍+350% revenue: Across active markets, with campaign automation, dynamic pricing, and better budget allocation running in parallel.

38% lower Cost of Sales: Growth came from running the right actions at the right margin, not from spending more to acquire sales.

300,000+ decisions automated in three months: Across 22 campaigns and 7 markets. None of them made manually.

Same team throughout: Operational capacity increased significantly. Headcount did not.