Accelerator, aggregator, agency, SaaS or an owned system: who keeps what?

Growth models for marketplace brands differ less in what they promise than in who ends up holding the seller account, the margin and the software. The table above lines up five of them, row by row. Facts about named companies come from their own websites and SEC filings, checked September 25, 2026, following our editorial standards. We run one of the five models, so we also say below when each of the others is the better choice, and when ours is not.

What are the five ways to grow a marketplace brand?

"Accelerator" covers several different businesses, which is why this comparison gets confusing; our glossary entry on ecommerce accelerators lists the meanings. Spreetail's guide to accelerators and aggregators draws the first line clearly: aggregators purchase and own the entire company, while accelerators buy products at negotiated wholesale rates and resell them, so the original business keeps its ownership (checked September 25, 2026). The same page describes Spreetail's own full-service model as buying a brand's inventory and running the whole operation.

• Aggregator: buys the brand. You sell the company, and the buyer runs it inside its portfolio.
• Reseller accelerator: buys the inventory. Pattern's 3P Accelerator page says "We purchase your inventory upfront" and lists forecasting, content creation, listing optimization, ad strategy and customer service among the work Pattern does. MarketLeap's FAQ says it buys your products at an agreed wholesale price and sells them under its own account (both checked September 25, 2026).
• Agency: rents you people. Your accounts and your stock; the agency's team runs ads, listings or account management for a fee.
• SaaS: rents you software. Your team does the work with subscription tools.
• Owned system: runs on your accounts. Software and AI agents are deployed on your own seller and ad accounts, and you stay the seller.

Not every program with "accelerator" in its name buys stock. Pattern's Form 10-K for fiscal 2025 describes its 1P Accelerator as access to its technology and services without Pattern purchasing inventory, with brands paying platform and service fees. Its 1P page is written for brands that sell wholesale to Amazon, so Amazon remains the retailer (checked September 25, 2026). Our 1P-to-3P transition guide covers moving from that model to your own Seller Central account.

Who is the seller of record in each model?

The seller of record is the business that sells to the shopper in its own name. Its name is on the offer, it sets the price, and the account's sales history and seller feedback belong to it. Settle this one row and most of the others in the table follow from it: who sets prices, who keeps the margin, where the data builds up and what happens when you leave. It is the first question to ask any partner, and the answer should be in the contract, not only in the pitch.

In a reseller accelerator, the seller is the reseller. Pattern's 10-K says that in the vast majority of its contracts it is the principal: it controls the product, assumes inventory risk and has discretion in establishing prices on marketplaces. The same filing lists, among its risks, marketplaces that "terminate or suspend our accounts". MarketLeap's FAQ says it sells under its own account, as importer and merchant of record. For scale, Pattern's Form 10-Q for the quarter ended June 30, 2026 says it sells products from more than 250 brands and operates across more than 70 marketplaces (checked September 25, 2026).

With an aggregator the question goes away, because the aggregator owns the company and everything in it. With an agency, a SaaS stack or an owned system, the seller of record stays your company. The difference between those three is who does the work and who owns the tools. An agency's staff work inside your accounts, SaaS tools connect to them through the marketplaces' APIs, and an owned system is deployed on them and run within rules your team approves.

Who keeps the retail margin, the data and the ad account?

Whoever sells to the shopper keeps the retail price. MarketLeap's FAQ puts its model plainly: it earns "a margin between the wholesale price we pay you and the retail price we sell at", with no monthly retainer or percentage of revenue. Pattern's 10-K says it generates the substantial majority of its revenue from consumer product sales on marketplaces; we do not estimate its spread. In the agency, SaaS and owned models, retail revenue lands in your own marketplace accounts and you pay fees out of it.

Sales history follows the seller account. With a reseller, it builds up on the reseller's accounts and you see it through its reporting: MarketLeap points brands to its MarketLeap Central dashboard, and Pattern's 3P page says brands have full visibility into performance. With SaaS, each tool keeps its own copy of the data it pulls. On Amazon, the selling partner authorizes each public application that reads its account through the Selling Partner API, and a private application is for the exclusive use of a single organization (checked September 25, 2026). That private route lets a system built for one brand connect to that brand's account through SP-API without a public app in between.

The ad account is the row to check most carefully with an agency. Amazon Ads' advertiser account guide describes agencies creating and managing client accounts, lets them bill ad spend either to the partner, at the manager-account level, or to the advertiser, and lists admin, editor and viewer roles (checked September 25, 2026). Both billing setups are legitimate. Before you sign, confirm the ad account is registered to your company, keep the admin role with your own staff, and know whose payment method carries the spend. Our guide to giving an agency access safely covers the Seller Central side.

With a reseller, ads run on the reseller's accounts and funding varies. MarketLeap says it funds all ad spend from its own margin. Pattern's 10-K says brand partners reimburse it for advertising costs incurred selling their products, and that brand partners invested more than $220 million in ad spend through its platform in 2025. The fair comparison is contribution margin after fees, ads, fulfillment and people, not top-line growth. Per unit, set the wholesale price minus your landed cost against the retail price minus marketplace fees, fulfillment, ads, returns and landed cost.

What does each model cost, and how is it paid?

Each model moves money in a different direction, so compare what reaches your bank account, not the headline fee.

Canopy Management, which calls itself a full-service Amazon agency, says three fee structures dominate PPC management: a percentage of ad spend, a flat monthly retainer, or a hybrid of a base fee plus a percentage of spend or a performance component (checked September 25, 2026). Before you sign, ask what the fee would be if your ad spend doubled. Our guide to what an Amazon agency costs covers published ranges. For SaaS, our SaaS stack comparison lists vendors' list prices and the meters that raise them.

Every model except the aggregator still needs people on your side. If you staff the work yourself, the U.S. Bureau of Labor Statistics puts the May 2025 median annual wage at $135,980 for software developers and $82,320 for logisticians, and benefits made up 30.0 percent of private-industry compensation costs in June 2026 (all checked September 25, 2026). Our comparison with an in-house team works through that math.

What happens when you leave?

Exit terms are where the models differ most, and they are easy to skip when a deal looks good. With an aggregator there is nothing to leave: the sale is final. With a reseller, notice periods are set by contract. MarketLeap's FAQ says it runs a rolling 30-day contract that either party can end with 30 days' notice. Pattern's 10-K says a substantial portion of its brand agreements allow termination for convenience on 60 days' notice, and that it relies on brands' obligations on promotions, buybacks and exclusivity provisions.

Leaving a reseller also means relaunching: its offers and selling history stay on its accounts, so you rebuild on yours. Leaving an agency or a SaaS vendor is simpler when the accounts were yours all along, provided you hold admin access and export your data before the end date; our guide to switching agencies without losing your data lists what to export. With an owned system, your listings and selling history stay put. Your accounts, data and custom code stay with you; the Growth OS base continues under its license terms.

Whichever model you pick, ask these questions before you sign:

When is each model the right choice?

Each of the five is the better choice for someone. We sell the last one, so weigh our view accordingly.

A reseller accelerator is the better choice when you want out of daily marketplace work and can live with a wholesale margin. An agency is the better choice when your systems already work and what you lack is specialists. SaaS is the better choice while your catalog and team are small. An owned system is the wrong choice if you want someone else to fund stock and ads, or if nobody on your team will own operations decisions. Our head-to-head pages on Pattern and MarketLeap go deeper, and Pattern alternatives lists options by model.

Is there an accelerator where the brand keeps its accounts, data and custom code?

Yes, in the owned-system model: you keep your accounts, your data and the custom code we build; the Growth OS base is licensed to you. Ecomsellertool is a tech agency that grows brands through technology. We deploy Ecomsellertool Growth OS on your own seller and ad accounts, then build the custom software and AI agents your operation needs on top. We never buy your stock or sell under our own accounts.

Growth OS is a base system for listings, catalog and pricing sync, orders and shipping, inventory and replenishment, warehouse and 3PL operations, margin-aware advertising, FBA reimbursements, reviews and reporting. Routine actions run within the rules you approve. Budget changes, purchase orders and unusual cases come back to your team with the evidence and a proposed next step. Custom modules cover what off-the-shelf tools miss in your operation, such as kits and multipacks that draw on the same components in your warehouse.

We have built on Amazon's seller APIs since 2017, shipped 50+ tools, served 100+ teams and built integrations for 20+ marketplaces. To see where your own operation stands, start with the free 24-hour diagnostic in the Ops Gap Diagnostic: connect Amazon with Login with Amazon, no password shared, and get a report within 24 hours of connecting, on business days. We only read data; we never change listings, prices, stock or ads. If you would rather talk it through first, schedule a call with the engineers who would build it. More about Ecomsellertool is on the homepage.