Confused - eCPM rates

[nomis5]

I have a large site about widgets, one of those pages ranks number 1 in Google for blue widgets.

I have another site which is solely about blue widgets, it ranks number 3 for that term. So I have slots 1 and 3 in the Google SERPS for blue widgets.

The large site has an eCPM which is almost exactly half that of the smaller site for exactly the same term. Both have the same settings in Adsense. So why does the smaller site, which ranks lower in the SERPS, have double the eCPM.

Think as much as I can, it doesn't make sense. It just seems that the smaller site is winning hands down for no apparent reason. If I can't work this out then it would seem that my best bet is to invest my time in lots of specifically targetted sites rather than one big one.

If it is of any concern, the smaller site has a site name which matches the search term exactly but without any spaces i.e. bluewidgets.com.

This is not a statistical anomally, the smaller site had 19,500 visits last month. Enough to ensure that the stats are resonably accurate.

Any thoughts?

[azn romeo 4u]

Different visitors demographics is one reason. Interest based ads is another. Smart Price could be another reason.

ECPM doesn't mean much. IMO CPC is the most important factor.

[CMidd]

You answered your own question. Specific sites or pages.

If a person lands on a generic or broad site they aren't really sure, they are just looking.

But if they know exactly what they want to buy, they get into shopping mode and their CTR for ads increase.

[HuskyPup]

IMHO as azn romeo 4u wrote:

CPC is the most important factor.

Ever since Stupid Pricing TM was introduced I have not been able to understand why my Coppermine image gallery's EPC beats ALL my other channels and sites hands down. The only thing that makes any sense is that most of its visitors are from the Canada, UK and US whereas all my other channels/sites have global visitors.

[nomis5]

Thanks for those ideas, all seem valid in different circumastances.

Both my sites are 85% UK visitors though so in my case I assume location of visitors is mostly ruled out. I think Husky Pup has identified why his pic gallery is so relatively profitable.

But the idea of how specific a site is, may be the reason for my two sites differences.

It'sa nightmare trying to work out which is best, multiple specific sites or one general site. A general site does seem to attract more visitors per subject area but a lower ECPM per visitor.