When do you give up on KWs that aren't converting?

[moderngamer]

Curious as to thoughts on removing or severely lowering bids on KWs that have good or high CTRs but haven't converted.

For example this month to date I have several keywords with CTRs ranging from 4-25% but 0 conversions.

At what point do you consider it a KW that doesn't convert well for your campaign?

I suppose the next logical move would be to lower the bids, and possibly adjust the landing pages but that can require significant time so the question becomes is this KW that hasn't converted worth all the time ($$) required to possibly squeeze something out of it? Hmm.

[Yoshimi]

What's your CPA target? This is what I would judge it on, if my CPA is £100 and I can get 10 visitors at £10 where 1 will convert, or 100 visitors at £0.10 where 1 will convert, I'm happy either way, but probably slightly happier with the 1/100 conversion, as that's great for increasing brand awareness too.

Additionally are you sure that this keyword isn't forming part of your buying cycle, if people in the research phase search for widgets and people in the buying stage search for red widgets, you will never see any conversions for the term widgets, but if you stop bidding on it you will lose sales.

[arieng]

When I bring on a new keyword, it gets 30 clicks at a very aggressive CPC. If it doesn't convert, the bid comes down to somewhere under $0.10. If it ever does convert at either bid price, the bid is adjusted according to ROI and modified on a weekly basis.