Unfair competition in digital advertising: what can your company do (and not do) on social media?

On social media, the boundary between aggressive marketing and unlawful competitive conduct needs attention. Buying a competitor's trademark on Google Ads, publishing disparaging comparisons or asking employees to pose as independent customers can create disputes, depending on the content and context. The reverse matters too: your company may be affected by misuse of its signs, with lost clicks, customer confusion and reputational harm.

Using fraudulent means to divert another business's customers for one's own or someone else's benefit is one form of unfair competition criminalised by art. 195, III, of Law 9,279/1996 (the Industrial Property Law), punishable by 3 months to 1 year of detention or a fine. Civil protection also covers unfair conduct (arts. 207–210), without making every civil violation a crime. This article examines ads using another company's trademark, comparative advertising, influencers and response options for your business.

Is using a competitor's trademark in ads and keywords allowed?

The STJ — Brazil's Superior Court of Justice — has recognised unfair competition where sponsored links use a competitor's trademark or business name to give the advertiser's site prominence. Its analysis considers competition in the same business sector and use capable of impairing the sign's identification and investment functions, encouraging confusion or exploitation of another's reputation. Generic industry terms are not automatically equivalent to another business's trademark. Hashtags, account names and product descriptions (“similar to [brand]”) require review of the rights and context: a legitimate reference or permissible comparison is not necessarily unlawful. Injunctions and damages depend on the requirements applicable to the case.

Comparative advertising: how far can I go?

Comparative advertising is not prohibited as such in Brazil: it must be objective, truthful and verifiable. Article 32 of CONAR's Advertising Self-Regulation Code requires advertisers to avoid confusion, discredit and unjustified exploitation of another's reputation; relevant differences in products, dates and prices must be explained. Articles 195, I and II, of the Industrial Property Law concern false statements or information about a competitor intended to obtain an advantage, not every criticism. Under CDC arts. 36–38, the sponsor must retain supporting data and prove advertising claims. A practical rule: keep reports, studies and sources, including dates and limitations, before publication.

Influencers, reviews and profiles: where does the risk live?

Three areas deserve review:

1. Undisclosed influencer advertising: advertising must be readily identifiable (CDC art. 36), using clear labels such as “publi” or “publicidade”. CONAR's 2026 guide distinguishes advertising based on reciprocal commitments, gift-prompted messages without an agreement to publish or control over content, and spontaneous content. Gifted-product posts also require transparency about the relationship, but are not all automatically ads. Brand, agency and creator liability depends on their involvement and the applicable rules;
2. Fake reviews: fabricating positive experiences for yourself or negative ones about a rival may constitute misleading advertising and unfair competition. Testimonials must be authentic and relevant commercial relationships transparent;
3. Copycat profiles and pages: accounts imitating a competitor's name, visual identity or bio may facilitate improper customer diversion. Preserve links, dates, screenshots and original files; a notarial record can support the evidence but is not the only admissible method and does not guarantee the outcome.

My company was attacked: what is the response plan?

Measures can be arranged to suit the case: 1) preserve evidence — URLs, dates, original files, reports and, where useful, a notarial record (ata notarial); 2) check ownership and scope of rights, content and responsible parties, considering a formal notice and platform reports (Google, Meta); 3) consider a complaint to CONAR where the ad falls within its remit; 4) assess court proceedings seeking urgent removal or cessation and properly supported damages. This is not a mandatory sequence: urgency may justify going directly to court. Material losses, valuation and harm to a company's reputation require separate analysis; criminal proceedings depend on the offence's elements and applicable procedure. CONAR's self-regulatory recommendations are distinct from Procon administrative sanctions and court judgments.

Hypothetical example: Tech Move Ltda. versus the bait ad

Hypothetical example: Tech Move Ltda., a São Paulo accessories retailer online, identifies a threefold increase in the cost per click on its trademark: a competitor buys “tech move” on Google Ads and advertises “Tech Move? Meet someone who delivers cheaper”. The company can preserve ads and quarterly traffic reports, check its rights and assess a notice, platform complaint and injunction application. Planning an initial response over 45 days or proposing a R$ 85 thousand settlement are illustrative assumptions only, not an actual case, a court deadline or a damages benchmark. Removal, settlement and damages depend on the circumstances and evidence.

The most common (and costly) mistakes

1. “Everyone buys the competitor's trademark on Ads.” Risk: industry practice does not remove the possibility of cessation orders and damages; a criminal offence requires separate proof.
2. Comparing without proof on file. Risk: the sponsor must prove the truth and accuracy of advertising (CDC art. 38). Missing support increases risk but is not automatically a confession.
3. Paying an influencer without addressing disclosure. Risk: each participant's disclosure, truthfulness and supervision duties need review, rather than treating the brand or creator alone as responsible.
4. Responding without preserving evidence. Risk: content can change or disappear. Preserve it promptly without delaying necessary urgent measures.

Actionable digital advertising compliance checklist

• A written keyword and creative policy: require prior review of references to third-party trademarks, including legitimate comparisons;
• A prior evidence file for every comparative piece (reports, surveys, dates);
• Influencer contracts requiring advertising disclosure and truthfulness;
• An internal ban on fabricated reviews — and monitoring of the ones received;
• A quarterly routine of searching for your brand in ads, profiles and marketplaces + a response protocol (evidence preservation and assessment of notices, platforms and court measures according to urgency).

Frequently asked questions

Is using a competitor's name in Google Ads a crime?

Fraudulent diversion of customers may fall under art. 195, III, of Law 9,279/1996, punishable by 3 months to 1 year of detention or a fine. The STJ has recognised unfair competition in sponsored links using competitors' trademarks or names under the conditions examined in its case law. Criminal liability requires proof of the offence's elements and the responsible persons' conduct; a civil violation does not automatically amount to a criminal conviction.

Is comparative advertising allowed in Brazil?

It may be allowed when objective, truthful and verifiable, without confusion, discredit or unjustified exploitation of another's reputation, under art. 32 of CONAR's Code and applicable legislation. Relevant differences in products, dates and prices must be explained, and supporting data retained. Under CDC art. 38, the advertising sponsor bears the burden of proving its claims.

What should I do if a competitor is using my trademark in ads?

Preserve the content, URLs, dates and available reports, and review rights in the sign and the competitor's conduct. Options include notices, platform complaints, a CONAR complaint and court measures. These routes need not all be exhausted before going to court where there is urgency. INPI registration and other relevant rights must be assessed for the particular case.

Does an influencer post have to disclose that it is advertising?

Yes, where content is advertising, it must be easily and immediately identifiable. CONAR's 2026 guide distinguishes advertising, gift-prompted messages without an agreement to publish or control over content, and spontaneous content. Posts mentioning gifted products should disclose the relationship behind the reference. Platform tools and understandable labels such as publicidade or publi should be visible where appropriate.

When should I see a competition lawyer in São Paulo?

Before launching campaigns involving comparisons, others' trademarks or influencers, and when a possible violation affecting the company is detected. Review should cover evidence, ownership of rights, urgency and available measures. Prompt action helps preserve relevant material but does not guarantee removal, damages or recovery of customers.

Online, an unfair advantage is traceable — for both sides

Ads, contracts, traffic reports and posts can provide relevant evidence, but not every digital trace proves a violation or its economic value by itself. Reviewing campaigns and retaining their supporting material helps prevent disputes and respond to misuse; screenshots do not automatically translate into damages.

At Falchet e Marques Sociedade de Advogados, a law firm in São Paulo (Av. Paulista), we work in competition law and digital advertising: campaign compliance, formal notices and court measures against trademark misuse, bait ads and unfair advertising — protecting the customer base your company has built.

Talk to our team on WhatsApp: +55 11 95901-1854 — tell us what the competitor is doing (or send the screenshots) and receive an assessment of the measures available.