Adwords Content - CTR?

[Quantam Goose]

I have dabbled with Adwords content ads on specific sites. The sites that I picked had daily volume in excess of 500k+. I quickly paused them because I was racking up about 20.00 per hour with no clicks. Can somebody give me an idea of the effectiveness of content ads? Are these high volume sites worth dealing with, or should I try and find more low volume, lower CPM sites? (The sites above all had in excess of $5.00 per thousand). Thanks in advance.

[jetteroheller]

I can not imagine how a very specific page could have such high volumes.

Such high volume sites could be for example news sites.

There are headlines with news, articles, but people visit the page to view news, not for the poor dog which broke his teeth while trying to bite a robot.

So they may not click on the Google ad

Teeth doctor for dogs
We solve any animal teeth problems
at low costs.

Complete different on a site about dogs, here makes this ad more sense and CTR.