Fluctuations in CPC rate

[Jon_King]

Given the same site and the same ads; what causes fluctuations in the CPC rate?

[dillonstars]

different visitors - and you can't tell which ad they click on...

[Visit Thailand]

Different locations someone clicking your ad in Thailand may well bring in a different CPC than someone clicking from the US.

[loanuniverse]

In addition to the geographical location of the visitors, you also have to account for:

Campaigns being upgraded/downgraded during the day so that sometimes a different ad will show up.

Each skyscraper has 4 ads, there could be a big difference between how much ad #1 pays to what ad #4 pays. Same thing for only the two ads in the banner.

The ads are targeted to the page first and to a lesser degree to the theme of the site. Not all pages get the same ads.

[cornwall]

When the big spenders, or those desperate to get top to the pile of ads, have used their budgets or stopped advertising, then the crafty advertisers that only have low bids in get their ads published.

Inevitably you will get your share of these.

In addition, times like weekends can get lower bid adverts published, if no others are around