Added keywords, CTR gone down

Effects of too many keywords on CTR

[silverbytes]

Added some 100 keywords to my campaign and my CTR went from 2,5% to 1%

My guessing is my ads are showing in not so close related searches and get few clicks. I see close related keywords with good CTR and many with 0%.

Should I just delete those new and keep my old good CTR?

[TerriGW]

We add relevant keywords frequently, and if I notice some CTRs dropping, I research and put in negative keywords to offset the unrelated searches the new words generate. Then the CTR goes back up and I keep the keywords we need.

[silverbytes]

Do you drop those with 1% or less
or just those 0%?

[TerriGW]

I keep any that are relevant to our site. Occasionally the customer (my boss) asks for irrelevant keywords which he figures someone who is searching that particular term will stumble onto our site, but it doesn't work that way -- they never click because they are not searching for us. Then I drop those keywords because they are always 0%. I have tried to explain why it doesn't work, but he has to see it on the reports. (What do I know?!)

The negative keywords (on relevant terms) help our campaigns filter the clicks we do not need, so normally I can keep the low CTR keywords because their performance increases as I add the negatives. I do not use exact match (instead of adding all the negatives) because we do want the ones searching for variables to see us as well. So far... success! :-)

[silverbytes]

Added negative keyword to campaigns, deleted those keywords with impressions but 0% CTR but my CTRs are very low this month... Some campaigns 2% others 1% and 0,5%...
What other things can I do to raise it?
I deleted repeated keywords on campaigns, so each adgroup points to a defined product.
Tried being very specific on ad copy and invite to action but doesn't seem to contribute to a better CTR...