More adsense blocks = low cpc?

Its true that more adsense blocks will give me a low cpc?

 

use the keyword search and rival many in low-and high click value

 

In my own findings, I was still getting about 25 cents per click regardless of how many ads I had in my sites.

 

its not always true ... it depend on the ads which is getting displayed at that time ...

 

generally yes but not 100%
adsense are actually showing the top earning ads to your site, mean if you have 3 ads, it shows the top 3 CPC ads that suit for your site, if you have more ads, the CPC will be lower

 

This fact is true, if for a given keyword you are very high on SERPs or for that matter on first position where advertisers might end up actually bidding for adspace on your site, for this to happen you have to be on first page and on first or second position, i am not quite sure about rankings below that. Higher bidding means you should have lesser adspace available on your site, so yes, if you meet all the criteria above then you can reduce the available adspaces (place only 1 or max 2 adsense blocks) and you should get higher click rates.

 

In general, more ad space will reduce your CPC. You will notice I wrote ad space not ad blocks. Three banners can have a total of up to 6 ads. Three large rectangles can have a total of up to 12 ads, a bid difference.

So how much does additional ad space reduce your CPC? It depends on the ad inventory and bids. For example, let's say you have a large rectangle on your site and you are wondering if you should add a second one.

In the first example, let's say the bidding is very competitve and the bids are $2.30, $2.28, $2.25, $2.21, $2.20, $2.18, $2.17, $2.16, $2.15, $2.14, $2.13, $2.12. In this case you would want to add a second or even a third large rectangle to the site. While the site CPC may drop slightly, you will likely see a nice increase in income.

In the second example, let's say the bidding is NOT very competitve and the bids are $1.30, $1.00, $0.80, $0.70, $.15, $0.10, $0.05, $0.01, $0.01, $0.01, $0.01, $0.01. In this case you would NOT want to add a second large rectangle to the site. Why? While you may pickup some additional clicks on the second rectangle, the CPC is likely to be very low. I would rather lose a 5 cent click and keep the visitor on the site with the hope that they will ultimately click an ad worth $1.00.

So how do you know what the bids are? While you will never know, you can make an educated guess. First, check Adwords for the keywords most closely related to your site. What does the CPC and competition look like. Second, you add the second large rectangle and see what happens. If the CPC drops through the floor, obviously there is not a lot of competition for your ad space and you are probably better off removing the second large rectangle. If the CPC only drops a little bit, there is plenty of competition for your ad space and you are probably making a lot more money off of your traffic.