Negotiation Guide

Earnout Structures in Online Business Acquisitions: How They Work and When to Use Them

Updated July 2026 · 9 min read · Deal Alert AI

An earnout is a deal structure where a portion of the purchase price is paid after closing — contingent on the business hitting agreed performance targets. Instead of paying $500K upfront, a buyer might pay $380K at close and up to $120K more over the next 18 months if revenue holds or grows.

Earnouts are common in online business acquisitions, especially when the buyer and seller disagree on what the business is worth. They close the gap — and they create alignment. But they also create risk, especially for buyers who don't know how to structure them correctly.

Definition: An earnout = deferred purchase price tied to future business performance. It is not seller financing. Seller financing is a fixed obligation the buyer must repay regardless of results. An earnout payment is conditional — if the business underperforms, the buyer pays less (or nothing).

Why sellers agree to earnouts

On the surface, earnouts seem like a bad deal for sellers. Why accept less money upfront? Because earnouts typically allow sellers to negotiate a higher total price than they'd get with an all-cash offer. If a seller wants $600K but the buyer's maximum cash offer is $450K, an earnout bridges the gap — $450K at close plus up to $150K in earnout payments if performance targets are met.

Sellers also agree to earnouts when:

The business is in a growth phase with recent revenue jumps that are hard to verify
They genuinely believe in the business's trajectory and want to be compensated if it continues
They need a fast sale and the buyer's cash offer is the only serious one on the table
The broker advises it as a way to maximize total exit value

Why buyers use earnouts

For buyers, earnouts serve two purposes: risk reduction and price alignment. If you're unsure whether a recent revenue spike is real and sustainable, an earnout lets you pay a premium price — but only if the spike holds. You pay for performance, not promises.

Common scenarios where earnouts make sense for buyers:

Revenue grew 60% in the last 6 months and it's unclear if that's real or manufactured
The business depends on the seller's personal relationships (e.g., a key contractor or advertiser that might not transfer)
The seller is claiming a multiple of projected future earnings rather than trailing performance
You're paying above-market valuation for strategic reasons (e.g., buying a competitor) and want downside protection

The three main earnout structures

1. Revenue-based earnout

The most common structure in online business acquisitions. The seller receives a fixed percentage of total revenue generated over an earnout period, typically 12–24 months after closing.

Example: Seller receives 15% of all revenue for 18 months post-close, up to a maximum earnout cap of $120K. If revenue holds at $800K/year, the seller earns their $120K. If revenue drops 40%, they earn significantly less.

Best for: Businesses where revenue is easy to verify (SaaS with clear MRR, content sites with display ad revenue) and where the seller can't easily manipulate the metric.

2. Profit-based earnout

The seller receives a percentage of EBITDA or SDE over the earnout period. Higher upside if the business grows; zero payout if it runs at a loss.

Problem: Profit is much easier to manipulate than revenue. A buyer with control over expenses can legitimately increase costs (new hires, tools, marketing) and reduce measured profit even while the business grows. Sellers should be extremely cautious with profit-based earnouts.

Best for: Buyers (not sellers). Revenue-based earnouts are safer for sellers.

3. Milestone-based earnout

A lump-sum payment when the business hits a defined milestone: retaining a key customer, maintaining subscriber count, launching a specific product, or reaching a revenue threshold. Less common but useful when there's one specific risk that justifies deferred payment.

Example: $50K paid at close, $50K more if the top affiliate partner relationship survives 12 months post-acquisition.

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How to negotiate earnout terms as a buyer

The earnout negotiation happens alongside the LOI. Key terms to nail down:

Earnout period

12–24 months is standard. Longer earnouts introduce more uncertainty for the seller and more administrative complexity. Shorter than 12 months may not give enough data. 18 months is a reasonable compromise.

Measurement metric

Always push for revenue over profit. Revenue is harder to manipulate and easier to verify independently via Stripe, PayPal, or ad network exports. Never agree to an earnout measured by "adjusted EBITDA" without very clear definitions of what adjustments are allowed.

Measurement period

Define exactly how performance is measured. Trailing 3-month average? Monthly totals? Calendar year? Make it explicit. Common approach: the earnout is paid quarterly based on actual revenue for that quarter.

Reporting and audit rights

As buyer, you'll have access to the books — but specify in the purchase agreement that the seller has the right to request verification of earnout calculations. This protects both parties and reduces disputes.

Earnout cap

Always set a maximum total earnout payment. This lets you model your worst-case total acquisition cost. An uncapped earnout tied to explosive growth could end up costing far more than expected.

Change of control protection

If you sell the business during the earnout period, what happens to the remaining earnout? Common terms: the earnout accelerates (seller gets paid out in full) or transfers to the new buyer at the original terms.

Risks for buyers — and how to protect yourself

The sandbagging problem

If the seller stays involved in the business during the earnout period (common in transition agreements), they could artificially suppress revenue to lower earnout payments. This is rare but happens. Protection: keep the seller's transition period as short as possible, and measure earnout against the business's performance under your operation — not a period where the seller controls the levers.

Revenue concentration during the earnout

A seller motivated to hit earnout targets might push revenue into the earnout window artificially — prepaid deals, early renewals, or one-time promotions that cannibalize future revenue. Protection: measure performance over a trailing period that extends past the earnout close, or use annual trailing averages rather than point-in-time snapshots.

Integration decisions that affect earnout

If you make changes to the business during the earnout that reduce revenue — rebranding, product changes, price increases — the seller may claim you sabotaged their earnout. This creates conflict and sometimes litigation. Solution: agree in advance which business decisions require seller consent during the earnout period, or keep earnout periods short (under 12 months) to limit the overlap.

Seller warning: Profit-based earnouts can be gamed by buyers through legitimate expense decisions. Push hard for revenue-based earnouts with clear definitions, or keep the earnout portion small relative to the upfront payment.

Typical earnout sizes in online business deals

Earnouts in online business acquisitions typically represent 15–35% of total deal value. A $500K business with a 25% earnout would close at $375K upfront with $125K at risk. This is large enough to matter to the seller (incentivizes good transition behavior) but small enough that the buyer has real skin in the game at close.

Very large earnouts — over 50% of deal value — are a red flag. Either the buyer doesn't have capital, doesn't trust the business, or the seller doesn't trust the buyer. If you're being pushed into an earnout that's more than half the price, revisit whether this is the right deal at all.

Earnout vs. seller note: what's the difference?

People confuse these constantly. A seller note is a fixed obligation — you agree to pay $100K over 24 months regardless of how the business performs. It's structured like a loan. A seller note doesn't protect buyers from business decline.

An earnout is conditional — you pay $100K only if the business hits targets. It protects buyers from overpaying for performance that doesn't materialize.

In practice, deals often combine both: a large upfront payment, a seller note for a stable middle portion, and an earnout for the "growth premium" component the seller is claiming.

Should you push for an earnout?

Push for an earnout when:

Revenue grew sharply in the trailing 3–6 months and you can't verify why
The seller is pricing the business on forward projections, not trailing performance
There's a key revenue driver (one customer, one traffic channel) that might not survive the transition
The asking price is at or above the top of market multiples

Don't bother with an earnout when:

Revenue has been stable for 24+ months — the trailing data is reliable
The earnout would be so small it creates complexity without real protection
You're buying a business you plan to change significantly — you'll never be able to separate your impact from the baseline

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Earnouts are a powerful tool when used correctly. They let buyers pay fair value for proven performance and growth premiums for actual growth — not seller projections. Structure them right, and they align everyone's interests. Structure them poorly, and you'll spend 18 months in spreadsheet arguments with someone you no longer need. Get the terms right in the LOI, long before closing.