There are probably two main ways of answering these questions. The first one is from the point of view of aesthetics and the second is about cold hard cash and whether it will earn you more money to have more ads or less.
1. Aesthetics – probably the most common complaint I hear against Adsense (and other types of ads) is that advertising is an eyesore and ruins the design of a page. I’ve read post after post of people complaining that they do not want to be exposed with ads and especially offensive to their sensitivities are pages that have ads all over them.
I have some sympathy for this view and its something that always weighs heavily on my mind as a blogger – how many ads are too many ads? The beauty (probably the wrong work in a paragraph about aesthetics) of Adsense is that it is customizable and ads can be made to blend into or contrast the design of a page. Even so, the more ads you put on your page the higher the chance you have of offending the those who are advertorially (I know its not a word – I’m being post-modern) sensitive.
Related to this is the theme of your blog. I have some blogs that I only serve one ad per page (or even no ads) simply because I don’t feel its appropriate to commercialize the blog at all.
2. Financial Considerations – believe it or not – but having more Adsense ads on your site can actually mean you earn less income from them! I know this sounds stupid and some of you think I’ve finally lost it – but its true, I found out for myself last week. Let me tell you the story.
Last week I decided to ‘tweak the ads on one of my blogs’. The blog in question had two ads per page, one in a banner ad at the top of the page and the other in a position within the content section of my blog. The ad within the content was my primary ad – the one that performed best (as previously discussed). Adsense allows three ads per page so the logic in my mind said ‘three ads will perform better than two’. So I cleverly decided to ad a small ad to my side bar (similarly to the one I have on this blog at present over on the left). I added it (with a label saying it was an ad) and smuggly went to bed imagining that I’d just earned myself a few extra dollars a day.
The next day I noticed that the Click Through Rate of my Adsense ads was lower than normal overall – so were earnings. I was not too concerned because it does tend to go up and down from day to day. The following day I noticed the same thing – lower CTR and lower earnings. Day three and I was starting to worry a little that something had gone wrong as the trend continued and I had little idea why. At first it didn’t even cross my mind that the new ad might be having any impact.
I checked the channels feature of Adsese at this point and realised that only one of the many channels that I track was lower than normal. It had halved its normal rate! Of course the channel that had decreased was the primary in content ad from my blog (my cash cow of the blog).
It only took me a few moments to work out why this had happened. You see the ad that I had added to my side bar was stealing ads from my primary ad in the content and leaving it with few, if any ads to serve. Let me explain.
The way Adsense works if you have more than one ad running on a page is that it will serve ads to the ad that it finds first on your blog. It fills up the first one first, the second one in the code second and the third one in the code third. If at any point it runs out of relevant ads it stops serving them and you either end up with a public service ad, an empty space or an alternate ad (depending upon how you configure your set up).
On that particular blog the code was in this order.
- 1 Banner ad
- 2 Side bar ad
- 3 In content ad
- 2 Side bar ad
- 3 In content ad
You can see what was happening – the banner ad got first priority and was always served ads. The side bar ad almost always got ads and the in content ad got them some (50%) of the time. Of course this left my primary position empty half of the time (not a wise move).
You can probably guess what I did faster than a speeding bullet – side bar ad was gone very quickly and the banner ad didn’t last long either. Now the in content ad is always full and I have moved a secondary ad further down the page. CTR and revenue are back up to normal (in fact they are up a bit).
So – take home message time. When designing the ads on your page rank your ad positions in terms of priority. Which spot do you want to get the first ads and always be full? Which are secondary spots that don’t matter so much if they are empty from time to time? Then check to see which order they appear in the code on your site. This is easily done. Simply select the ‘view source’ option in your browser. This should open a window that shows you the back end of the page you’re viewing – find the google adsense code and work out which is which (you should be able to tell by the size of the ad). If your primary ad isn’t the first one you might need to make some changes either to where you place your ads or to how your blog is configured and serves the code.