Why EPC is so low?

if I have plenty of inventory for the pages...

[itisgene]

I just put the multiple ad units (3) on one of my sites. It used to have better EPC than now. The average EPC of this site dropped to about 50-60% level of last year. I had adsense on this site since June 2003. If you have any theory other than "Smart Pricing", let me know.

I think it is not smart at all. It just tries to lower the EPC whatever you do...

FYI, I just put the 3 ad units and one of the main pages has 14 ads(4 + 5 + 5) on one page. I know it may be too many. But hey, that is the maximum allowed. And the page is quite crowded anyway. It has about... three fold of content on the page.

I will let you know How it goes.

[Never_again]

A drop in your EPC should be expected. Instead of just showing 4 or 5 ads, you are now showing 14 ads. This means that your are displaying a lot more low paying (low EPC) ads since you have to drop in to the lower bid area to stock your ads. People click on these ads which brings down your average EPC.

The most important number is your total income. Has it gone up? I'd guess it has not because having more ads on a page doesn't mean more people are going to click. Since EPC is down, income may also drop. I'd rather have 4 or 5 higher paying ads on a page than 14 low (on average) paying ads.

[itisgene]

I just put the additional ads yesterday.
I was talking about EPC drop BEFORE this multiple units. Yes, I believe it will decrease the EPC further. I want to see if it increases overall earnings...

[alika]

From AdsenseAdvisor in [webmasterworld.com...]

If I may throw my 2 cents in, you might consider measuring the results of multiple ad units by examining your overall revenue as opposed to EPC and eCPM. These figures are based on ad units, rather than page performance, so multiple ad units on a page will alter their value. I'll pass your thoughts on to the team, so that they can come up with solutions to reporting based on the way publishers use their reports.

With multiple ad units, your EPC will decrease because it is measured per ad units. With up to 3 ads per page, your EPC becomes diluted. As ASA said above, I hope G will come up with a metric that measures EPC on a page basis, not by ad unit as it currently stands. This way, we will be able to more accurately learn the value of our pages.

[Never_again]

With multiple ad units, your EPC will decrease because it is measured per ad units.

Wow, that is amazing. I'm glad you pointed out ASA comments, but does that really make sense? EPC is not provided by Google. You have to calculate it yourself. The way I do it is to divide total income by the number of clicks for the same period. CPM is a different story -- ASA's comments makes sense for this calculation.