Forum Moderators: martinibuster
eCPM is a synthesis of all four figures -- EPC, CTR, earnings, and number of impressions -- which are all taken into an account in eCPM.
eCPM is a synthesis of all four figures -- EPC, CTR, earnings, and number of impressions -- which are all taken into an account in eCPM.
Eh? It's (earnings/impressions)*1000 isn't it? Clicks and ctr don't come into the equation - just earnings and impressions.
Seleno - I never use day to day figures in any meaningful data analysis. I generally use monthly data. I don't think anything can be drawn from comparing two days.
I have to say that the ctr is - erm, rather high.
eCPM = (Earnings / Impr) * 1000
eCPM = CTR * EPC * 10
CTR = (Clicks / Impr) * 100
CTR = (eCPM / EPC) / 10
EPC = Earnings / Clicks
EPC = (eCPM / CTR) / 10
Earnings = EPC * Clicks
Earnings = eCPM * Impr / 1000
And so on.
About the first question, it's normal to see the contrary, for example high EPC (CPC) with high CTR -and high eCPM-, but there is a variety of different cases, with many other factors -known and unknown- involved (advertiser bids, smart pricing, etc.).
Eh? It's (earnings/impressions)*1000 isn't it? Clicks and ctr don't come into the equation - just earnings and impressions.
Why is eCPM so special? Because, as I already wrote, eCPM is affected by all the AdSense parameters. If EPC changes, eCPM changes too. If CTR changes, eCPM changes too. If number of impressions changes, eCPM takes it into an account.
CTR alone is useless. You can earn more on a day with 0.1% CTR than on a day with 90% CTR (due to different EPC).
EPC alone is useless. In total you can earn more on ads with EPC of $0.1 than on ads with EPC of $10 (due to different CTR).
Comparning earnings between two days may be misleading, because number of impressions may be different between the two days.
The bottom line, only eCPM can be reasonably compared between two days.
I'd also like to make the point that eCPM is a standard way of comparing different revenue streams. For example, having several different pages with several different ad providors and widely varying site traffic/clicks. By using the eCPM figure you can easily compare all of these to see which ones work effectively.
The other point to make is that like epc, eCPM is useless in itself. My top channel for eCPM today is showing $273.98 - but it's only had two clicks. I use ALL metrics in tandem to get the full picture.
Earnings = eCPM * Impr / 1000
Earnings = CTR * EPC * Impr / 100
eCPM = CTR * EPC * 10
That is to say, for higher earnings, we need higher eCPM and/or more impressions. For higher eCPM, we need higher CTR and/or EPC.
It's "and/or" because for example we can get higher earnings from a good eCPM, even with fewer ad impressions, among many other different possibilities and combinations.
In general, for CTR we need that the users read the ads (reducing ad blindness with AdSense optimization, good placement, etc.) and also that they like the ads and click them (with targeted ads, that is topic-focused pages rather than general ones). For EPC (CPC) we need conversions and therefore a good smart pricing effect. And, finally, more impressions mean more traffic, of course.
It seems useful to remove ads from pages with very low eCPM, if it cannot be improved even after trying optimization. (You can try again ads on some of those pages from time to time, to verify any possible performance improvement). There is a controversy about a possible beneficial smart pricing effect from removing non-performing ads, but in any case -even without that possible effect- your readers will be grateful to see only the ads that they like and therefore click on, with frequent conversions from truly interested users. And happy users are the key to more and good traffic. ;)
Especially useful equations are:
Earnings = eCPM * Impr / 1000
Earnings = CTR * EPC * Impr / 100
eCPM = CTR * EPC * 10
To be honest, although these formulae do indeed come up with the correct numbers, the issue is being confused.
Earnings = epc * number of clicks.
That's how Google calculate the amount that ends up in your bank account each month. Therefore both epc and number of clicks have great importance.
eCPM can have little relation to bottom line cash figure. For example, two days this month with virtually identical eCPM, bottom line cash figure on one of the days is 25% higher. Coversely, two days this month with similar bottom line cash figure, and vastly different eCPM.
Although I look at eCPM all the time, the way I use it mostly is in deciding what ad blocks stay, and what ones I delete.
The example I quoted earlier in the thread for 2 clicks and $200+ eCPM. I know that channel isn't visited a lot, but when it is, clicks usually pay well. Therefore, despite the very low earnings it will stay because it has a high eCPM and therefore is not likely to get the rest of the site smartpriced down the toilet. Contrast that with another page where the earnings are OK, but the number of page views and low number of clicks mean it's got a very poor eCPM. Therefore there is every chance that the poor performance on that page is going to get me smartpriced so it gets deleted.
People here can get hide-bound into relying solely on one metric. I believe you have to use ALL of the available statistics and ways of measuring site performance to tune your site for the optimum bottom line cash figure. Therefore, whilst eCPM is an important metric, epc and clicks have equal significance. And that's the point people here forget.
epc matters the most to me, because that's what the advertisers are actually paying per click.
seleno, as was pointed out earlier, comparing day-to-day is not accurate... if anything, the numbers you posted are so close that you should be happy about it.
eCPM can have little relation to bottom line cash figure. For example, two days this month with virtually identical eCPM, bottom line cash figure on one of the days is 25% higher.
epc matters the most to me, because that's what the advertisers are actually paying per click.ctr give you valuable information
If you earned $40 per click and I earned just $1 per click, I could still earn much more than you even if we had the same traffic. CTR is similarly useless for comparisons.
ecpm is the most worthless
It is all quite easy to understand, I believe.
I'm not trying to pick a fight here. I am trying to make the point that when trying to view the bigger picture, all of these metrics have their purpose, and they are all fairly meaningless in isolation. eCPM has it uses, as do epc and ctr. Bottom line cash figure is what matters most. That's the figure that will pay for the family holiday in Corfu my wife is trying to book. No other metric will pay for this other than bottom line cash.
well
thanx every one
so...more ctr=less money
Sometimes, but usually not.
all of these metrics have their purpose
(If you really need to have the last word, go ahead. I am not going to try to explain it over and over again.)
so...ctr is 8 and ecpm 10, will earn less than 2% ctr and 10ecpm
No, both earn exactly the same. If eCPM is $10 then, whatever the CTR, you are earning $10 for every thousand impressions.
If you are thinking about using Adwords for arbitrage, I suggest you get to grips with all the terms used & how Adsense works first, otherwise you might find yourself losing a lot of money.
but you just told us that comparing just two days worth of earnings is misleading, which is indeed correct... so there is no way that you can justify using ecpm for a situation that isn't valid in the first place.
the reason that base stats are so valuable is because they tell you exactly what needs to be improved... got low ctr? try improving your page design, or even the source of your traffic... good ctr but low overall earnings? look at the epc history, the volume of traffic, add ypn to the pages with the lowest earnings, etc.
>>>My top channel for eCPM today is showing $273.98 - but it's only had two clicks.<<<
exactly my point, thank you... it boggles the mind to think that people make decisions about their websites based on an uncontrolled data source like ecpm.
seleno, juan_g also made some really good points about developing your site, based on stats.
