Filtering keywords and knowing which keywords are converting and which ones are loosing money is the key to any PPC account optimization strategy.
Filter keywords that are generating clicks and cost, but no conversions at all . Doing this based on 1-2 days or weeks of [...]

Effective Bid Management - Step Three: Filter keywords that generate Conversions but Negative ROI or higher than your target CPA.
If your PPC account is structured keeping your business goals in mind and you have a solid keyword list in the account, you will only have a handful of keyword fitting [...]

Effective Bid Management - Step Two: Filtering Keywords with No Clicks and No Conversions
Filtering Keywords with No Clicks & No Conversions identifies irrelevant Keywords in an account or Keywords that are not getting enough exposure - mainly due to low Max. CPCs. It also identifies Keywords that have lost traffic and/or conversion based on previous [...]