How often should I display ads?

on heavy traffic pages with low CTR

[mike73]

I have a blog server. The blog pages get about 40K page views per day with CTR less than 0.3%.

Is there a magic formula, like only display ads 50% of the time, or something, that will increase CTR and earnings?

Any tips are appreciated.

[dataguy]

I try to only display ads to a unique visitor 4 times, then I switch out the ad supplier to display different ads. I've seen it done many different ways, but this is what has worked best for us.

[MikeNoLastName]

We don't bother with cookies or tracking to identify uniques in real time. We simply alternate the ads, on a particular page, between G and affiliates, or other sources every other, or every third impression (regardless of who requested the page). Sure by shear chance the same person may see the same ad 2-3 times, but our post-mortem analysis showed that was about the limit, which works out the same as dataguys strategy without the tracking complexity. We found this at least doubled our CTR in most places.

Rule #1 should be to make the ads more noticible by placing them as close to the readers' eye path as possible. This will depend on your particular site. Either near the menu or in the middle or end of articles works good (the beginning is worst as readers are anxious to get right to the point and even if they see the ad at the top, they probably forget to click by the time they are done reading.) There always seem to be certain page types which simply do not produce CTs. On those we put impression based ads.
We have a sitewide avg page CTR over 7%.
Rule #2 is to structure your pages so that G picks out the top keywords to select ads for.
Good Luck

[mike73]

Thanks for the tips, guys. I tweaked the ads so some of the ads only appear 70% of the time, and CTR has already gone up quite a bit, relatively speaking.