How does CPC go down?

[ryeguy]

How is CPC driven down? I know it's by getting a good CTR, but is it per campaign or per keyword? For example, let's say I have "blue widgets" as a keyword, which has a high CTR. I also have 9 other keywords on my account with terrible CTR. Will my CPC for "blue widgets" be low while the other 9 are high, or will my whole campaign's keywords, including "blue widgets", be high because overall the campaign is bad?

Is there any downside to having a lot of keywords that aren't getting many impressions (not saying that the CTR is bad, just that no one is searching for them)?

 

[HarveyJ]

ryeguy: Depends on the ad platform, but the common thread in all of them is CTR.
Google will lower your CPC if you've got a page that they think is high quality by whatever they deem that to be.
Facebook is based almost solely on CTR in the first day of running in so far as I've noticed.
MSN's seems to have a fair bit based on your SERP in Bing in what I've noticed as well.

etc

 

[indianman]

Delete the ones with low CTR (if you are sure the low CTR is not because of your ads) and the ones not getting any impressions.

 

[globalim]

cpc goes down from high ctr which is a given but also long term ad placement. Keep you ad running for a few weeks and your cpc will drop drastically