Many popular browsers now have some form of ad blocking add-ons or extensions. Firefox's most popular is Adblock Plus. Google recently announced that the Chrome browser will support ad blocking extensions despite the fact that Google is making much of its money off advertisements. Will this type of technology eventually cost advertisers on the internet?
There are a variety of advertisement models on the internet, many of which are based on performance. Someone will be paid if there is a sale or paid if there is some sort of click on the advertisement. Each of these takes a willing visitor of that webpage to actually take some sort of action. It seems obvious that someone who does not want to see ads is typically not one who will click on them let alone buy anything. They are simply not interested in offers online and subsequently choose to ignore them.
Ironically, these types of viewers using ad blocking technology can actually save advertisers money. First, these viewers won't accidentally click on an ad which might cost the advertiser money. At times, this can happen on accident especially if the page is still loading and the mouse pointer changes its position.
Some advertisements are based on impressions, or number of views. If you are paying by impression as an advertiser, you do definitely do not want to pay to show ads to people who do not want to see them.
Other forms of advertising like pay per click advertising have some performance mechanics related to them. If your ad is not bringing in clicks, generally the cost of the ad goes up or its position goes down. Those opting out of seeing ads would not hurt the advertiser whereas if they saw them and did not click it actually could.
Realistically, there probably will not be a time where everyone uses ad blocking. Even if there was, ads could still exist within text links embedded in content which would be impossible to actually block unless someone just decides not to surf the internet anymore.
Are ad blocking extensions going to hurt those who advertise on the web? Maybe, but in some case these advertising models might actually help advertisers because it simply blocks the people who have no desire to buy products online.