Large vs. medium rectangle results

[JohnKelly]

On my sites the large rectangle (336x280) gets a higher CTR but lower EPC. The medium rectangle (300x250) gets a higher EPC but lower CTR.

I'm guessing that the higher EPC with the medium rectangle is because it can display image ads, which are presumably bid higher. But I don't understand why the CTR would be lower... perhaps also because image ads get clicked less than text ads?

Since the sizes of these two rectangles aren't that far apart, could there be any other reasons for the discrepancies between EPC/CTR?

[Brett_Tabke]

And you have been testing by exchanging the two in the exact same position? Having you tried moving the location of the ads and swapping them at the new location? What does that do to the ctr.

> images

Yes, classic banner blindness has lead to a massive declined in image click through rate the last 5 years. 97-00, you could get 20% ctr a lot of times accross a wide network. Today - you are lucky to get 1% average on most notext based gfx.

[JohnKelly]

And you have been testing by exchanging the two in the exact same position? Having you tried moving the location of the ads and swapping them at the new location? What does that do to the ctr.

Yes, the exact same position, even experiented with alternating between the large and medium rectangles, with each assigned to a unique channel. Results are pretty much as described.

CTR is higher with lg rectangle, lower with med rectangle. EPC is the opposite. I may just use eCPM, though I wonder about higher CTR yielding "better" ads eventually.

[Swebbie]

Might be that the larger block has 4 ads vs. 3 on the smaller block. I'm guessing that the third ad on the smaller block pays more than the fourth ad on the bigger block. Could be wrong.

[webnoob]

> Might be that the larger block has 4 ads vs. 3 on the smaller block

i don't think so.. my cpm seems to be higher with the 728 leaderboard than the 468 banner... you'd think the banner would pay more because less ads.. turns out to be the other way around.. who knows what google is doing.

[musiqqueen]

You said your earnings are lower, but the click thru rate is higher for your larger rectangle and for your medium rectangle the click rate is lower, but the earnings are higher. From this we know that advertisers are paying more for the keywords that are associated with your site when you are use the medium rectangle, but more people are clicking the larger rectangle.

It maybe that the larger rectangles are showing more ads that are related and therefore they are getting clicked more, but making a lot less.

What are the positioning of your ads?