Sestimi.pl: moved from manual decision-making to automated sales scaling — increasing revenue by 350% in 30 days

TL;DR SECTION:

• How Sestimi scaled its marketplace activities without increasing headcount thanks to automated decision-making and execution
• Merchantee took over day-to-day decisions on pricing, discount campaigns, and PPC optimization
• Over 300,000 product-level decisions were automatically evaluated by the system within 3 months, with no manual work
• Dynamic pricing generated 2% of total revenue as pure incremental profit
• The result was +350% revenue growth and a 38% reduction in Cost of Sales within 30 days

CONTEXT: SESTIMI AND MARKETPLACES AS A STRATEGIC CHANNEL

Sestimi.pl is a fast-growing fashion retailer that has built its long-term growth and expansion strategy on marketplace platforms. Sales are generated through strategically selected online marketplaces across Europe, with a portfolio of tens of thousands of products.

With a broad assortment and multiple markets comes complexity: competitive price changes, different types of discount campaigns, varying promotional conditions, the need to manage advertising efficiently, and at the same time stay within defined margins and internal strategy.

This brings a reality that all large-scale marketplace sellers know well:

• Each marketplace works differently.
• Each market has different pricing dynamics, campaigns, competition, and customer behavior.

Yet all decisions must fit into one internal strategy, respect margins, budgets, and target profitability – on a daily basis.

THE REAL CHALLENGE: HOW TO SCALE MARKETPLACE ACTIVITIES AND THE DAILY DECISIONS BEHIND THEM

Sestimi knew exactly what it wanted to do on marketplaces.

It had clearly defined pricing policies, discount rules, and advertising budgets.

The real issue was not the decisions themselves – it was their volume and frequency.

As the number of products, markets, and marketplace activities grew, it became necessary every day to:

• react to changes in competitor pricing,
• decide whether to participate in dozens of discount campaigns,
• manage advertising investments,
• and at the same time ensure that every action made sense in terms of margins and Cost of Sales.

Every decision – whether reacting to competitors, joining a discount campaign, or investing in promotion – had to be made in the context of internal rules such as margins, budgets, and acceptable selling costs.

Remaining consistently active and competitive on marketplaces such as Allegro and Kaufland is demanding in itself.

TECHNICAL OPERATIONS WERE HANDLED BY INTEGRATORS. BUT THEY DID NOT SOLVE DECISION-MAKING AND EXECUTION AT SCALE

Sestimi was already using integration platforms.

They helped with the technical side of selling – listings, orders, basic automation.

But they did not address the key question:

Without a system capable of taking over this decision-making burden, part of the marketplace sales potential remained untapped.

Not because data or strategy were missing, but because there was no capacity to execute them in practice.

MERCHANTEE AS AN AGENTIC MARKETPLACE SPECIALIST

Sestimi therefore deployed Merchantee not as another tool, but as an agentic marketplace specialist – a software layer that connects decision-making with automated execution.

Instead of manually controlling individual actions, Sestimi defined in Merchantee:

• pricing guardrails,
• minimum prices for discount campaigns,
• Cost of Sales limits,
• and the overall sales strategy and business exceptions

MERCHANTEE THEN:

The strategy remained in Sestimi’s hands. Execution and daily decision-making shifted to Merchantee.

PRODUCTS WERE NOT ADDED TO CAMPAIGNS MANUALLY. MERCHANTEE DECIDED ON ITS OWN.

The biggest impact on growth came from automated discount campaigns.

Sestimi uploaded so-called campaign limits into Merchantee – the lowest prices at which it was willing to include products in campaigns such as Allegro Days or Black Week.

Merchantee then:

• checked available campaigns across marketplaces and markets every day,
• evaluated their conditions and current market prices,
• compared them against predefined rules,
• and independently decided whether a product should be included in a campaign or blocked to protect margins.

OVER 300,000 OFFERS EVALUATED AUTOMATICALLY IN 3 MONTHS

Between October and December 2025, Merchantee:

Hundreds of products were automatically included in campaigns where it made sense.

Thousands more were blocked to prevent margin strategy violations.

No manual work. No team expansion.

DYNAMIC PRICING GENERATED 2% OF REVENUE AS PURE EXTRA PROFIT

Dynamic pricing was also part of the agentic approach and:

Merchantee updated inputs multiple times per day and monitored competitor prices several times per hour.

Based on defined rules, it decided whether to:

• match competitors,
• undercut them to maximize the chance of winning the Buy Box,
• or increase prices where the market allowed.

The additional margin generated by price increases was pure profit – without a negative impact on sales volume.

PRODUCT SEGMENTATION FOR MORE EFFICIENT PPC INVESTMENTS

Merchantee also evaluated customer behavior and product performance daily and automatically segmented products into:

SUPERSTARS

High-conversion products worth actively promoting.

CONTENDERS

Products with high interest but low sales. Removing them from PPC led to immediate cost savings with no revenue impact.

COLD STOCKS

Products with minimal interaction, suitable for visibility testing or listing optimization.

Thanks to this segmentation, Sestimi invested PPC budgets where they delivered the highest business impact.

RESULT: MORE ACTIVITY, THE SAME TEAM

Already within the first month after launching key features, Sestimi recorded: