DEV Community

Cover image for Why ads follow us everywhere?

Posted on

Why ads follow us everywhere?

Have you ever wondered how you see the most relevant ads all over the web, whenever you've searched something recently? Let's say, you're searching for a pair of shoes or a nice party dress online and for some reason, you had to leave. However, items matching the products you were looking for keep following you across on other sites like Facebook, or some random site or keep appearing in other apps like search, email.

All these online targeted advertisements use data from your browser to make marketing more personalized. Special algorithms then look at your website visits and searches over time to predict your preferences and show ads you may be interested in.

This week I was searching for a vacation place in Europe and I started seeing - more ads from airline companies and the blogs telling the best places to visit in Europe.

There are many people who are still unaware of the fact that the social network tracks and records a list of their interests in order to target advertising. So, let's know more about it.

Who is tracking?

Many companies try to track you, but the main culprits are Facebook and Google.


Have you ever wondered how Google and Facebook are generating profits even after offering their app services for free? How do they earn their profits?

At their core, Google and Facebook are advertising companies — ads contribute more than 80 percent of their revenues.

So what will make an ad company attractive to the advertisers?

“Ad clicks!”

Advertisers love the company which helps them boost their sales. So advertisement companies start showing ads in a patterned manner rather than showing irrelevant ads. This was possible only by tracking users and creating a profile on them.
So gradually we became the product of these companies even without our approval.

If You're Not Paying For It, You Become The Product!

How targeted ads work

One may expect Facebook to have a profile on you, based on your actions within Facebook. It, in fact, tracks you across the web, on various other websites through the social plugins (the like and share button you see in almost every website).

Google tracks you easily by the huge google ecosystem deeply embedded in our life. Google knows what you are thinking (chrome, google assistant, google search), where you are headed to (Maps), etc.

The personalized ads are a result of cookies and an IP address. Cookies are text files in your browser that track the information you’ve searched. For example, when you searched for a Nike shoe of size 37, the cookie is stored like this:

_amazon_search: c2hvZT1uaWtlO3R5cGU9RjtzaXplPTM3

Here the search value is encoded, it can be decoded to show the final value like this: shoe=nike;type=F;size=37

Your IP address is kind of like your house address and shows where you are located. The balance between both of them is what gives the information to advertisers.

There are two ways online ads can target you: through social networks and through your browser.

On social media sites, there are ads that function based on who logs in. If I log in as Meghna, there is information collected about me that is used to target ads. For example, if I post a lot of pictures of myself coding, or sitting with a laptop, social media networks could then scan the pictures.

As a result, the next time I log into Facebook, I could see ads for programming courses, or some tech-specific tools to purchase.

Advertisements also target you through your browser. The cookies and IP address records websites you visit, how long you were on it, etc.

How much?

Now we know that companies do track you, but how much do they know?

Google knows:

Where you have been, your web activities, all the apps you use, all of your YouTube history, all your calendar activities, email, notes, files in drive and photos stored, even after you have deleted them. So practically, Google knows everything that needs to be known about your digital life.

What can you do about it?

You do have the option to ask Google to stop tracking your web and other activities by pausing everything.

Next step is to stop using the Google search engine. One can start using other search engines like DuckDuckGo, Startpage - they show search results from Google, but it doesn’t let Google know who searched.

Next backbone of Google in data collection is Chrome. Google Chrome is based on the open-source project Chromium. So you can use other chromium-based browsers such as brave. Mozilla Firefox is also a good privacy-focused browser.

Install ad, tracking script blockers such as uBlock Origin and Ghostery to remove the tracking scripts, Facebook social plug-ins.

How to stop targeted ads

  • Turn off cookies

  • Use a browser plug-in to limit data tracking.

  • Turn off targeted Facebook ads

  • Go incognito

  • Limit site linking: Avoid using the “login with Facebook or Google” feature on websites you visit.


Once we searched Google, but now Google searches us.

Nothing is free in this world, the more data Google gets on you, the more profitable it will be.

The loop of more data => more ad clicks => more profit, ignites the competition in tracking you more.

Next up: do you know how content-creators sell space in their website to ad companies? I will cover it in my next post. Stay tuned!

Top comments (1)

skyandsand profile image
Chris C

Thanks Meggie!

I have several bookmarks on ad-blocking and anti-tracking technology.

Web 3.0 has become a bloated mess and privacy nightmare due to this sort of stuff.

It has its place but 2020 poses a risk to anyone who uses a cell phone, workstation, social media, or Amazon shopping