Ad blockers - Friend or Foe?

11 November 2005

Adverts are used throughout the web to make money for the site owners, offset some of the costs of none-commercial sites. Whether this is good or bad can depend upon whether you own the website, or are a visitor.

I include adverts on some of my webpages, so obviously I am not against them as such. Saying that I don't make any money out of the websites and have not yet even received a single payment from the adverts I display. Even when they do start paying money, they are unlikely to cover the costs I incur in running the sites.

The adverts that I do not like when visiting other sites are ones that either create a pop-up window, or those that move around on the screen, getting in the way of the page. When placing adverts I try and make them fairly discrete, either by using relevant ones within the text, or by placing them around the outside of the screen to not detract from the main content. I am more likely to click on ads on other websites when they do the same.

As a result of the intrusive adverts there is now a market in ad-blocking software to remove the adverts before they are downloaded. I had one installed on my home machine without even realising. This was included in Norton Internet Security (I have the 2004 version), and was enabled by default.

This hasn't really caused any problems, until I tried to view a site that I am currently updating. For a commercial site that I am updating I developed the site on my Thinkpad, and had tested it using a few different operating systems / browsers, but all on machines without ad blockers. I then tried to view the page on my desktop machine, but was surprised to see that a picture was missing.
At this point I didn't know the cause, so tried reloading the page, and viewing the xhtml source only to see that the entire image tag was missing from the code. Eventually I figured out that this must have been blocked by Norton Internet Security and in the log it indeed said that the file had been blocked. Looking at why this was blocked it gave the reason that it was because it was an image that was 250 pixels by 250 pixels.

This appeared to be a very risky strategy for identifying adverts. There are no links associated with the image, it wasn't being served from a different server and didn't use any flash, it was just the image size that triggered the ad-blocker. As a result perhaps I've been missing other images from within webpages, as there was no indication that the image had been removed. I have therefore turned off the ad blocking "feature".

The image size was specifically chosen as a good size to base all future photographs from. Should I therefore resize my photographs to a more unusual size, just because of this ad-blocker? If it is that simple to get around the ad-blocker, then perhaps this is just what the ad sites will do to make sure their ads still show.

If you are using Norton Internet Security, and think you're missing out on some important pictures, that might be exactly what you are doing!