Detection

Can a Brand Know It’s Being Counterfeited Without Buying Product?

Yes. Your customers are already telling you, and the places counterfeiters sell are open to anyone.

Chris Anderson, Ph.D. · Cyber Investigation Services (CIS) · CIS Brand Briefing No. 4 · October 2026

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The Short Answer

Yes. Only a test buy proves a particular item is fake. You do not need one to see strong signs of a problem. Your customers are already telling you, and the places counterfeiters sell are open to anyone with a browser.

Brands often assume they need paid monitoring to find out. To learn whether you are being counterfeited, you need an hour and three habits: read your one- and two-star reviews, search for your brand where counterfeiters sell, and watch the price. This paper shows why each works, with the public record behind it.

Read Your One-Star Reviews

Start with your one- and two-star reviews, on every marketplace that carries your product. Your customers are already telling you. Many buyers who get a fake never say “fake.” They say your product changed.

An industry research firm, Gartner L2, read more than 350,000 Amazon reviews of products sold by third-party sellers. It reported that “a third of all unique products listed by third-party merchants garner a review that calls the product, often a fashion or beauty item, a ‘fake’ or ‘counterfeit.’”1 University researchers have built a model that estimates how likely a product is to be counterfeit from its customer reviews alone.2 The U.S. distributor of the “Love to Dream” baby swaddle learned of a fake from one customer call. It then found more complaints online about the fake: zippers falling off, and a neck opening too large or too small.3

Search your reviews for fake, counterfeit, not authentic and knockoff. Then keep reading, because many buyers who get a fake never suspect one. They think your product got worse. Look for these four complaints:

  • A repeat buyer says it changed. Someone who has ordered your product again and again says this one is different: the packaging, the feel, the result. A loyal customer knows your product. The FDA asks patients the same question about medicine: “Does the drug or packaging look different than what you normally receive?”4
  • A short count. Fewer pills, pieces or ounces than the label says. Today’s manufacturing standards do not allow this. Federal law requires the quantity on the label to be “separately and accurately stated,” and the national standard for checking packages holds every lot to it.5 A short package is a strong warning.
  • A strange color, taste or smell. The product does not look, taste or smell the way yours does. For anything people eat, drink or put on their skin, act on this one first.
  • Fake or counterfeit, in so many words. Some buyers do spot it. Take them at their word and look at who sold to them.

You will know. Nobody knows your product better than you do: every formula, every package change, every supplier. When a complaint describes something that does not sound like your product, trust that. One review proves nothing. A run of them is a signal.

Look Where Counterfeiters Sell

Counterfeiters do not sell only on Amazon. The U.S. Trade Representative’s 2025 list of “notorious markets” for counterfeiting names online marketplaces including DHgate, Taobao, Pinduoduo and IndiaMART.6 Reporters have documented Facebook and Instagram, including Marketplace, as major venues for fakes.7

Court records show the same spread. We counted the defendants in 75 public “Schedule A” counterfeiting lawsuits, which name many online stores at once in a list attached to the complaint. The defendants were accused of selling on more than ten sites.8

DEFENDANTS IN 75 SCHEDULE A LAWSUITS, BY SALES CHANNELShare of 14,053 defendant entries in the court filingsAs of September 28, 2026Amazon36.3%eBay12.6%Temu10.9%AliExpress9.6%Walmart7.3%Wish3.9%Own website3.3%Alibaba2.7%DHgate2.1%Shein0.8%

DEFENDANTS IN 75 SCHEDULE A LAWSUITS, BY SALES CHANNEL

Share of 14,053 defendant entries in the court filings

As of September 28, 2026

  • Amazon36.3%
  • eBay12.6%
  • Temu10.9%
  • AliExpress9.6%
  • Walmart7.3%
  • Wish3.9%
  • Own website3.3%
  • Alibaba2.7%
  • DHgate2.1%
  • Shein0.8%

Figure 1. Where sued counterfeit sellers were selling

Even in cases chosen for Amazon sellers, more than half of the defendant entries were on other sites.

Source: our count of public court filings (note 8). Amazon’s share is high partly because we chose cases that named Amazon sellers. Entries with no marketplace label (9.5%) and five smaller sites (1.0% together) are not shown.

Search your brand and your best-selling products on eBay, Temu, Shein, AliExpress, Walmart and Facebook Marketplace, as well as Amazon. Compare what you find with what you sell and who you sell through.

Watch the Price

The government’s own consumer advice says the same thing a brand owner sees first. U.S. Customs and Border Protection: “if the price of a product seems too good to be true, it probably is.”9 The Federal Trade Commission warns of “ads for brand-name products at unusually low prices.”10

You know your cost, your wholesale price and your authorized sellers. A listing well below what any authorized seller could charge, from a seller you have never heard of, deserves a closer look. A low price alone is not proof. Next to a run of “fake” reviews, it is a strong signal. A test buy still decides.

What Knowing Gets You

None of this costs money. It costs an hour, and it tells you whether there are signs of a problem. A clean hour does not prove there is none. It does not tell you who is behind the listings, how much they sell, or which of them are worth pursuing. Reporting a listing can get it taken down. In our experience, it rarely stops the seller behind it.

If the reviews and the searches say you have a problem, the next question is who, and how big. That is the work we do.

Put Your Brand on Our Free Watch List

If counterfeiters are selling under your brand, you should know it before your customers do. We always watch for free. When fakes put your customers at risk, we warn you and send you a CIS Consumer Safety Review: who is selling, where they ship from, and what it would take to stop them.

We package the intelligence to attract contingency attorneys to take your case. Our fee comes only from the recovery. Many counterfeiting problems can be resolved with no money out of your pocket: the attorney pays the upfront costs and takes them back from what is collected.

About the author. Chris Anderson, Ph.D., founded Cyber Investigation Services, a Florida limited liability company, in 2010 and leads it as CEO. CIS is an eCommerce consumer safety and national security intelligence firm. For 16 years Chris has built intelligence on the sellers behind counterfeit marketplace listings.

Put your brand on our free Watch List

Already seeing fakes? Write to me at chris@cyberinvestigationservices.com.

Sources

  1. 1Retail Dive, “Amazon’s fakes problem hits lower-priced brands hardest,” August 24, 2018, reporting a study by the research firm Gartner L2 of more than 350,000 reviews on third-party listings. Industry research, not a government finding. https://www.retaildive.com/news/amazons-fakes-problem-hits-lower-priced-brands-hardest/530875/
  2. 2Hayden Wimmer and Victoria Y. Yoon, “Counterfeit Product Detection: Bridging the Gap between Design Science and Behavioral Science in Information Systems Research,” Decision Support Systems, vol. 104, December 2017. https://www.sciencedirect.com/science/article/abs/pii/S0167923617301720
  3. 3CNN Business, “Fake and dangerous kids products are turning up for sale on Amazon,” December 20, 2019. https://www.cnn.com/2019/12/20/tech/amazon-fake-kids-products
  4. 4U.S. Food and Drug Administration, “Counterfeit Medicine,” content current as of December 8, 2025. https://www.fda.gov/drugs/buying-using-medicine-safely/counterfeit-medicine
  5. 5Fair Packaging and Labeling Act, 15 U.S.C. § 1453(a)(2): “The net quantity of contents (in terms of weight or mass, measure, or numerical count) shall be separately and accurately stated.” https://www.law.cornell.edu/uscode/text/15/1453 . National Institute of Standards and Technology, Handbook 133, Checking the Net Contents of Packaged Goods, 2023 edition: the average contents of a lot must at least equal the declared quantity, and no single package may fall unreasonably short. https://www.nist.gov/system/files/documents/2023/02/10/2023%20NIST%20Handbook%20133.pdf
  6. 6Office of the U.S. Trade Representative, “2025 Review of Notorious Markets for Counterfeiting and Piracy,” March 2026. Temu, Shein and AliExpress are not on the 2025 list. https://ustr.gov/sites/default/files/files/Press/Releases/2026/2025%20Notorious%20Markets%20List%20(final).pdf
  7. 7Organized Crime and Corruption Reporting Project, “Facebook and Instagram Major Markets for Counterfeit Goods,” February 19, 2022. https://www.occrp.org/en/news/facebook-and-instagram-major-markets-for-counterfeit-goods
  8. 8Cyber Investigation Services, count of defendants in 75 Schedule A trademark cases whose seller lists were free and unsealed on CourtListener, a public archive of federal court records, as of September 28, 2026. A seller named in two cases counts twice. The cases lean toward the Northern District of Illinois.
  9. 9U.S. Customs and Border Protection, “This Mother’s Day, Be Alert: Counterfeit Goods Sold Online,” May 3, 2021. https://www.cbp.gov/newsroom/local-media-release/mother-s-day-be-alert-counterfeit-goods-sold-online
  10. 10Federal Trade Commission, “How to avoid an online shopping scam this holiday season,” consumer alert, November 25, 2025. https://consumer.ftc.gov/consumer-alerts/2025/11/how-avoid-online-shopping-scam-holiday-season

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