I have heard a lot of bloggers complain about people coming to their blog and using various Ad-Block software to avoid being served advertising. I used to be in that camp myself, until I figured out that they are actually a benefit!
In web advertising there are several types of advertising models:
1) Affiliate Sales
This category covers web companies such as Amazon who allow a web publisher to put advertising blocks on their website that are designed to send people to another site to buy things.
When a purchase is made, the referring website gains a commission on the sale.
2) CPM (Cost-per-Impression)
This category covers advertising that webmasters want. You get paid a set amount of money to show an adv a set number of times. It may be as low as $10 for 10K impressions or it could be even higher.
Most bloggers will not be able to get this sort of advertising until they have 500K or more hits every month.
3) CPC (Cost-per-Click)
This is the category most bloggers fall under and is the chief method used by AdSense. AdSense does offer CPM advertising but that is based on advertisers telling Google to put their ads on a certain page.
This article is going to be written under the assumption that you are using a CPC system.
A factor in CPC advertising is CTR (Click-Through-Rate.) This is an indicator of how well your advertising units do. If 100 people come to your site and 20 of them click on advertising you will have a CTR of 20%. Of course many people do not click on advertising or may not click on it until they decide to leave your website.
What that means is that if 100 people come to your website, look at 10 pages each and then 20 leave via an advertising link your CTR will be 2%! The same number of people, the same number of clicks, but your CTR fell through the floor.
Now, what if 80 of those people used ad-block software? Why you would be back up to a 20% CTR!
See, CTR has an effect on the types of advertising you get. The higher your CTR the better advertising you will get.
Now, there is one caveat to that though: A high CTR can also get you flagged for possible click-fraud.
I know it sounds weird, you want a high CTR for advertising but if it gets too high you might get dropped for click-fraud!
As long as your clicks are legitimate you have nothing to fear from having a high CTR. If your clicks are bogus though... You will be quickly banned.
How do they know if your clicks are bogus? Several ways:
1) If a high number of clicks come from the same IP.
2) If a high number of clicks come from different IPs in the same network/geographical location.
3) If the same IPs click your ads every day.
4) If an advertiser notices all the clicks from your site have a 100% bounce rate.
There are other ways for the advertisers to know if click-fraud is involved, so don't do it!
In my own experience, I have had days with 50 advertising clicks and my payout has ranged from a couple of dollars to almost twenty dollars. The big difference has always been my CTR. A high CTR day has always beaten out a low CTR day with the same number of clicks.
It is also important to look at what sort of content was being served up on those days before you make a comparison. A story about new shoes is going to attract a different type of advertising than talking about the new Nintendo Wii! Likewise the CPC earnings can vary highly between keywords present in your content.
When I did my testing I accounted for this and used days where similar stories were "hot."
This is why I now like surfers who use ad-block software. If they have no intention of clicking on my ads then I don't want them ruining my CTR but viewing ads!