A separate-but-related question from "what is a patent troll?" is "how exactly do they make money?" The mechanics matter because the failure modes — what makes assertion campaigns expensive or risky for the troll — are exactly where defendants find leverage.
This is the operational deep-dive. For the definition and a high-level overview, start with what is a patent troll?.
The core economics
Three numbers explain the entire business:
- Cost to file a patent infringement complaint. About $400 in court fees, plus a few thousand in attorney drafting time. Total: $5,000-$15,000 to get the first complaint on the docket.
- Cost to defend through trial. $1M-$5M+ depending on complexity. The AIPLA Economic Survey is the standard reference for these numbers.
- Settlement value. $50,000-$500,000 for the typical NPE demand against a mid-sized company.
The asymmetry: filing a suit is cheap, defending is ruinous, and settlement is calibrated to be just below the cost of fighting. Defendants do the math and pay. The patent's actual validity is secondary — a junk patent generates settlement income exactly the same way as a strong one, because nobody pays $1M to test a $200k demand.
This is the entire model.
The corporate structure
A typical patent assertion involves a stack of entities, each serving a specific function:
The shell LLC
The patent owner of record. Usually a Delaware or Texas LLC with no employees, no physical office, and a registered agent address. Files the lawsuit. Receives any settlement.
The shell exists to limit downside. If the defendant prevails and seeks fees under § 285, the shell has nothing to pay. Defendants who win uncollectible judgments learn the hard way that the assertion entity was always insolvent on paper.
The parent or aggregator
The company that owns the shell. Often itself owned by another holding company, which is owned by a fund. The parent typically:
- Holds dozens or hundreds of patents, sorted by industry
- Has a few employees — usually licensing executives and outside-counsel relationships
- May or may not be publicly identified in the litigation pleadings
Patent assertion entities like Acacia Research, IP Edge, and Marathon Patent Group are publicly known; Intellectual Ventures (founded by ex-Microsoft CTO Nathan Myhrvold) is the largest aggregator and operates more discreetly. The aggregator distributes patents to shell LLCs as needed for assertion campaigns.
The funding source
Increasingly, third-party litigation finance firms bankroll NPE suits in exchange for a cut of any settlements or judgments. Funders like Burford Capital, Parabellum Capital, and Omni Bridgeway (formerly Bentham IMF) maintain entire patent-litigation portfolios. They do diligence on the patent's strength, the target list, and the settlement potential before writing checks.
This professionalization changed the troll landscape in the late 2010s. Pre-finance, individual NPEs were limited by their own capital. Post-finance, a credible patent + a credible plaintiff could attract eight-figure war chests.
The inventor
Often long divorced from the patent, sometimes deceased. The original inventor — frequently an individual researcher or a small startup — sold or assigned the patent years before the assertion campaign. They might receive a small royalty cut, but the strategic decisions (who to sue, when to settle) are made by the aggregator.
How they get the patents
Most assertion campaigns aren't built around patents the troll invented. They're built around patents the troll acquired. Sources, in rough order of volume:
- Bankruptcies. When a tech company fails, its IP portfolio gets liquidated. The Nortel patent auction in 2011 (won for $4.5 billion by a Microsoft-Apple-RIM consortium) and the Kodak portfolio sale a year later are landmark examples. Patents that originally cost $50k-$200k each to prosecute can sell for a few thousand each in bulk lots after a bankruptcy.
- Individual inventors. Small inventors with single-patent portfolios who can't afford to enforce themselves. The aggregator buys for $20k-$100k upfront plus a percentage of future royalties.
- Defensive divestments. Large companies (think IBM, Microsoft, Apple, Samsung) periodically sell patent bundles to clean up portfolios. Some bundles end up at NPEs.
- Patent brokers. Specialized middlemen — ICAP, Ocean Tomo, and similar firms — broker patent sales between inventors and aggregators.
- Claim purchases. Direct purchase of unasserted claim rights from a patent holder.
The acquisition cost is the defining number. A $30,000 patent that produces three settlements at $200,000 each is roughly a 20× return, in a year or two, with most of the work done by lawyers on contingency.
The assertion campaign
A typical campaign looks like this:
1. Industry survey (months 1-2)
The aggregator's team identifies an industry and a feature area where the patent reads. They build a list of 50-200 potential defendants — companies that ship products with the targeted feature.
2. Reverse engineering (months 2-3)
Outside counsel and technical experts produce claim charts — spreadsheets that map each claim limitation to specific functionality in each accused product. (How to read a patent claim → — the same skill on the defense side.) Some campaigns invest heavily here; others produce thin charts good enough to clear Rule 11 standards.
3. Demand letter wave (months 3-4)
The aggregator sends polite-but-firm demand letters to the entire list. The demand is calibrated to be cheaper than fighting — typically $50,000-$500,000 per defendant. Roughly a third pay quickly to make the letter go away. Cost to the troll for this entire wave: a few hundred thousand dollars in attorney time. (What to do when one of these arrives at your desk →.)
4. Litigation against holdouts (months 4-12+)
Of the defendants who didn't pay, the aggregator selects 10-30 to sue, prioritizing companies with deep pockets and the worst defenses. Lawsuits filed in plaintiff-friendly venues — historically the Eastern District of Texas, now also Delaware and the Western District of Texas. (The patent litigation lifecycle → covers what happens phase by phase.)
Most of these settle during discovery once the cost picture is clear. A few proceed to claim construction; fewer to summary judgment; fewer still to trial.
5. Roll forward (year 2+)
The assertion campaign continues against new entrants in the industry until the patent expires or is invalidated. Successful campaigns generate settlement income for 3-7 years across dozens of defendants.
What it looks like in numbers
A representative (composite, illustrative) campaign:
- Patent acquired for $40,000.
- 150 demand letters sent. Total demand-letter cost: roughly $300,000 in attorney time.
- 50 settlements at an average of $80,000 each. Revenue: $4,000,000.
- 20 lawsuits filed. 18 settle on average for $250,000 (some lower, some higher). Revenue: $4,500,000.
- 2 lawsuits go to summary judgment. Both lost — patent invalidated. Cost: roughly $1,500,000 each, $3,000,000 total. No revenue.
- Net to the aggregator and funders: roughly $5,000,000 over 3-4 years on a $40,000 acquisition.
Real campaigns vary wildly. Some patents generate far more; others lose money. The portfolio approach lets aggregators absorb the losers.
The litigation-finance angle
Third-party finance changed the math in the late 2010s. Pre-finance, an NPE with a good patent but no capital had to use contingency-only counsel and accept lower settlement targets. Post-finance:
- Funders provide $1M-$10M war chests against patents they think will hit.
- Plaintiffs can pursue cases all the way to trial without settlement pressure.
- Defendants face plaintiffs with effectively unlimited litigation budgets.
The Federal Circuit and several district courts have started requiring disclosure of litigation funders, partly in response to this dynamic. Disclosure regimes vary — Western District of Texas standing orders are among the most aggressive.
Defensive aggregators
The other side of the market. Several categories of defensive entities exist specifically to counter NPEs:
- RPX Corporation. Buys patents that NPEs are likely to assert and licenses them to its members defensively. Subscription-based.
- Unified Patents. Files IPR petitions against high-risk NPE patents on behalf of a member coalition. Doesn't buy patents — strikes at them through the PTAB.
- LOT Network. A defensive cross-license network. Members agree that if one of them ever sells a patent to an NPE, every other LOT member gets a free license. Removes the resale value of patents to trolls.
- Allied Security Trust (AST). Bulk-buys patents at auction and grants licenses to members.
Together, these defensive aggregators have meaningfully reduced the supply of high-quality patents available to NPEs, especially in big-tech industries.
What's changed (and what hasn't)
The post-2010 reforms each took a slice out of the model:
- AIA (2011). Created IPR, tightened joinder. NPEs can no longer mass-sue 50 defendants in one complaint.
- KSR (2007) + Alice (2014). Made obviousness and § 101 invalidity easier in district court and at the PTAB. Particularly hard on software-method NPEs.
- Octane Fitness (2014). Made fee-shifting under § 285 more achievable. Trolls now risk paying defense fees if they push too far. The 2014 Lumen View v. FindTheBest fee award against the holder of US Patent 8,069,073 was one of the earliest applications of the new standard.
- eBay (2006). NPEs almost never get injunctions. The kill-switch threat is gone.
- TC Heartland (2017). Tightened venue. Reduced (but didn't eliminate) Eastern District of Texas dominance.
What hasn't changed: the core cost asymmetry. Filing is still cheap. Defending is still ruinous. NPEs have adapted to settle for less, faster — which keeps the model profitable at lower margins per case.
What flips the model
For an individual defendant, a few moves materially reduce the troll's expected value:
- Fight one. A defendant who fights through to summary judgment and wins puts the troll's portfolio at risk — an invalidated patent is worthless going forward against everyone.
- File IPR. A $300k IPR can kill a patent the troll planned to monetize for years.
- Coordinate. Joint defense groups share research and costs. The troll's economic model depends on uncoordinated defendants.
- Document misconduct. Builds the § 285 fee-shift case. The credible threat shifts settlement leverage.
- Public exposure. Trolls dislike publicity. EFF's "Stupid Patent of the Month" series and similar efforts have killed several high-profile campaigns.
- Pre-built defenses. When invalidity dossiers exist for a patent before the troll asserts it, the cost to fight collapses. That's the structural fix this site is built around. Browse the database of analyzed patents, or add a patent we haven't covered yet.
Bottom line
Patent trolls operate on a cost-asymmetry arbitrage: they pay $30,000 for a patent and demand $300,000 from each of fifty defendants, knowing that nobody will spend $1,000,000 to prove the patent is junk. The reforms of the past twenty years have raised the cost and risk of running this model, but haven't ended it. The structural fix is making invalidity defense affordable enough that trolls can't rely on settlement income from junk patents.
Not every patent litigant is a troll — many patent owners enforce their rights to protect real products and research investments. The analyses on this site are tools for evaluating any patent assertion on its merits.
For the definition and a higher-level overview, see what is a patent troll?. For what to do when one targets you, see what to do if you get a demand letter.
This article is for general education and is not legal advice.