Retargeting Explained

According to statistics only 2% of website visitors will end up using their credit cards to buy something, while the remaining 98% will just have a look and leave. Of course this is bad news for website owners. Most of the case these websites pay big money to drive traffic. These checks are in majority given to Google for its notorious AdWords service.

So if you think about it for a second you will see how much money being dumped with no return on investment. Suppose you paid 1000US$ for Google AdWords, you will be shocked to know that only 20US$ will generate income for you and the remaining 980US$ will simply evaporate.

Retargeting is a solution devised to this type of problems. It consists of an agency that builds and indirectly connects a network of publishers and advertisers. The process of retargeting goes like the following:

• You go to the advertiser website let’s say Amazon.com
  
  
• Amazon will insert a special script from the retargeting agency into your browser; this script will in turn insert a cookie, known to the browser as third party cookie, with a unique id. This way the retargeting agency will uniquely identify you. This is a completely harmless because it does not gather any personal information; it simply assigns you a unique number.
  
  
• As you browse the Amazon web site and look at the different products, the script transmits those data to the retargeting agency.
  
  
• Suppose you have added a product to your basket and proceeded to checkout, but for some reasons you did not complete the purchase operation. For Amazon you are a lost customer. However, the retargeting agency knew what product you were about to purchase. Using the cookie it has inserted into your browser it will be able to identify you again whenever you land into one of its publisher’s website.
  
  
• To continue with our example, suppose you left Amazon.com and went surfing the web until you pass through Yahoo.com. It happens that Yahoo.com and Amazon.com deal with the same retargeting agency. Because of that famous cookie (inserted when you were at Amazon.com) the retargeting agency will know that you were the person who did not complete the purchase at Amazon.com and will display to you an advertisement about the product you were about to buy.
  
  
• This technique has proven effective to the advertisers in converting potential customers into buyers.

In case you need to have a concrete sense of what is happening behind the scenes, you can tell your browser to clear all cookies (caution clearing all cookies will cancel automatic login on some sites, so you will need to manually re-login). If you are using Firefox you can go to the menu “Tools > Options”, choose “Privacy tab” then click on “Show Cookies” and then click on “Remove All Cookies” in the Cookies dialog box.

Once you do that, go to Amazon.com then reopen to Cookies dialog box again take a note with the available cookies and remove them all. Go to Yahoo.com and again open the Cookies dialog and verify that there is at least one cookie in common with the Amazon.com.

If you are frightened by the above and fearing of being tracked, don’t be. Actually this is a safe procedure and usually there is no harm from that. Quite on the contrary, it might help websites know the behavior of their visitors in order to serve them in a better way.

Facebook also uses this technique with partner sites. To know what it looks like, login to your Facebook account and then without logging off go to CNN.com; chances are that you will be told what article(s) your friends liked over there.

In case all of that still make you fear for your privacy, it is useful for you to know that you can stop this by simply telling your browser to reject third party cookies. On Firefox you can go again to “Tools > Options > Privacy” and uncheck “Accept third-party cookies”.

Internet Explorer 8 has a feature called "Private Browsing" that allows you to browse the web without being tracked.