How to block pop-under ads on Boston.com (and other sites)

Pop-under ads are browser windows that open in the background while you view a web site. Boston.com was on of the first sites to start using this technique almost 10 years ago, and it is still as annoying today as it was back then.

Why is it annoying? Because when you close the original browser window with the news article that you just read, and any other windows you had open, you will find these ads plastered over your desktop, just when you think you are done cleaning it up. Often this ads run on a timer, meaning that they don’t appear right away, but only after you have been looking a at page for a while. It is a sneaky practice, and it is controversial, and I don’t like it.

“But online businesses depend on the advertising revenue!”  is a common response. Nonsense! By that argument one could say “Don’t lock up the thieve, his livelyhood depends on stealing!”. Nobody would take such an argument seriously. The need for ad revenues is legitimate but does not justify any means conceivable. If a web site, news outlet or not, can’t be run profitably without resorting to sneaky and unethical practices, it does not deserve to be online. So why tolerate sneaky ads if we don’t want them?

Well, we don’t have to tolerate them any longer. Here is how:

1. Start your favorite text editor as an administrator. Notepad is fine. To run it as an administrator in Windows 7 or Windows Vista, right-click on the item in the start menu and select “Run as administrator”.
2. Click on file/open and navigate to the folder c:/Windows/system32/drivers/etc, then open the text file named hosts (without a file extension).
3. Paste the following lines at the bottom of the file:
    127.0.0.1 cdn.optmd.com
    127.0.0.1 as.casalemedia.com
    127.0.0.1 a.tribalfusion.com
    127.0.0.1 a1.zedo.com
    127.0.0.1 c1.zedo.com
    127.0.0.1 c5.zedo.com
    127.0.0.1 d3.zedo.com

   Save and close the file

4. Restart your browser
5. The change will cause most requests for ads to fail and the ad page will not get served.
6. From now on, most pop-under ads will open a blank window, which means that there is still a window, but you will not get a cookie and you will not have to look at the pesky ads anymore.
7. Eventually you will find new pop-under ads appear from hosts that are not in the above list. Just add them to your hosts file, all with the IP address 127.0.0.1. Unfortunately there is no support for wildcards in the hosts file, which means that each individual URL has to be added if it is to be blocked.