Has it ever happened that you visit an online store and then see its products everywhere? In many cases, that happens because of advertising cookies (or marketing cookies), which store information while you browse to identify your activity on the web.
The point is that, depending on how they’re configured, they can also have implications for your privacy. So in this article, we’ll help you understand what they are and what options you have to manage them with more control.
Advertising cookies—or marketing cookies—are text files saved in your browser to show you relevant ads. Their function is very specific: storing data such as on-site searches, views, or clicks.
In this way, advertising systems can capture behavioral signals within your browsing and recognize your device on subsequent visits.
Marketing cookies help identify browsing patterns. If you have a website or ecommerce, this lets you measure campaign performance and make advertising more precise.
Therefore, they’re commonly used for:
Remarketing/retargeting. They identify when a user views a product or page and then trigger related ads while the user browses that same site or others.
Frequency capping. They control how many times the same ad is shown to avoid excessive repetition and improve user experience.
Campaign measurement (basic attribution). They record clicks or visits from ads and help identify whether an action followed (e.g., a purchase or sign-up).
Ad personalization. They use browsing signals to adjust which ads a user sees based on interests, habits, or recently viewed topics.
Audience segmentation. They group browsing signals to classify users into segments (for example, people interested in travel, shopping, or technology) and target ads to similar profiles.
Often, advertising cookies are integrated into a digital marketing strategy to segment, measure, and personalize ads.
On a website you might use marketing cookies and others that help measure site performance or enable basic functions:
Type of cookies | Purpose | Require consent? | Privacy impact | Common example |
Marketing (advertising) | Track behavior and show personalized ads (including across sites) | Yes | High (profiling and tracking) | Facebook Pixel / remarketing cookies |
Analytics (performance) | Measure how users interact with a site (visits, time, sources) | Generally yes (depends on regulations and configuration) | Medium (on-site activity tracking) | |
Functional | Remember preferences to improve experience (language, settings, session) | Not always, but must be disclosed and allow control | Low to medium (depends on data stored) | Remember language or sign-in |
Beyond their purpose (marketing, analytics, or functional), advertising cookies can also be classified by who creates them: first-party/third-party.
First-party cookies. Created by the same website you’re visiting. For example, when a page remembers language or session data.
Third-party cookies. Created by a domain external to the site you’re browsing. For example, when you enter an online store and later see ads for that same product on other pages.
Why does this matter in 2026?
In 2026 this difference matters more because Google announced it will not remove third-party cookies by default in Chrome as previously anticipated. This means they remain part of the ad ecosystem, albeit with more controls and restrictions.
Therefore, management is in your hands (as a user). And if you run a website, you can continue adapting advertising in an environment with more privacy tools, blockers, and regulation.
Advertising cookies can be useful for the industry, but they also pose real privacy risks for users, including:
Cross-site tracking. Some tools can follow a user’s activity across different pages to learn what they visit, their interests, and which ads they see—even if the user doesn’t notice.
More detailed profiles. Over time, browsing can be used to infer tastes, purchase intent, or routines, potentially shaping a user’s digital identity.
Misuse or data leaks. While the risk is low, any system that collects data can be exposed to configuration errors or unauthorized access.
This isn’t about alarmism, but about understanding what can happen when advertising depends on tracking and profiling.
The key to handling advertising cookies correctly is letting the user clearly decide what to accept or reject. Whether you manage a website or simply want to understand how consent applies, a good banner or CMP should have:
Clear alternatives by category. The ability to accept or reject by purpose (marketing, analytics, functional) without bundling everything into a single option.
A visible, easy “reject” button. It should be as accessible as “Accept,” not hidden or confusing.
Periodic review/updates. Ideally review and prune cookies regularly (at least once a year) to avoid piling up unnecessary tools or old tags.
In Mexico, personal data processing is governed by LFPDPPP. It establishes basic principles of transparency and accountability when a site collects information from its users.
For more detail on how information is handled at DolarApp, you can consult the Privacy Policy (Mexico).
If you want to reduce tracking and better control the ads you see online, the most practical approach is to review your cookies in the browser.
Here are some steps:
Check the site’s cookie banner. Enter the site and open the preferences panel. If there’s a category like “Marketing” or “Advertising,” you can usually disable it there.
View cookies saved by a site. Go to your browser settings and look for “Cookies” or “Site data.” There you can see which domains stored information and delete just the site you’re interested in.
Block third-party cookies. Enable third-party cookie blocking to limit tracking across different sites. This often reduces “stalker” ads without breaking everyday browsing too much.
Delete cookies for a specific site (the most recommended option). If a site bombarded you with ads or you want to “reset” your browsing, delete only that domain’s cookies. It’s quick and won’t affect everything else.
Delete all cookies (if you want a full clean-up). You can delete all cookies from the browser, but note this may also sign you out and remove saved preferences (like language or logins).
Verify the result. Reload the site or return later. If the control worked, you should notice less personalization or less repetition of ads.
In general, blocking third-party cookies and deleting cookies for a specific site is usually enough to regain control. Though on many pages, the banner lets you decide what to accept or reject without affecting the rest of your browsing.
Advertising cookies are part of how digital advertising currently works, but that doesn’t mean you must accept them without understanding them.
Once you know what they are, how they’re used, and what they imply for your privacy, you’ll be able to make better decisions while browsing. The important thing is to keep control—whether you prefer to customize your consent or block third-party cookies at the browser level.
Do you manage a website?
Apply best practices in transparency and cookie management to strengthen user trust in your brand. Also, tools like Ahrefs can help you spot technical improvements that impact site performance and visibility.
In turn, DolarApp can be your ally when managing your income in digital dollars or euros. Beyond receiving, you can also send USDc/EURc and make conversions at a fair exchange rate.
In the terms and conditions you can see how cookies are used within DolarApp’s service.
Advertising cookies are files that store identifiers in your browser to record how you interact with a page. They’re used to show relevant ads and measure campaigns; they do not access messages or passwords.
Not necessarily. Marketing cookies are defined by their purpose: advertising and measurement. Third-party cookies are defined by who creates them: an external domain. There can be first-party or third-party marketing cookies.
You can keep using the site, but you’ll see less personalized ads and possibly more repetition. Some campaign measurements will be limited, and remarketing usually decreases.
Open the banner and go to “Customize” or “Preferences.” If categories like “Marketing,” “Advertising,” or “Ads” appear, it’s a sign the website uses marketing cookies.
Block third-party cookies in your browser and delete cookies for the domain you care about. Also use “Customize” in banners to reject marketing and keep only what’s necessary.
Sources:
Google announcement on third-party cookies
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