Can anyone give me a rule-of-thumb strategy ?
Re: Can anyone give me a rule-of-thumb strategy ?
I only wish questions like this were as easy to answer as they are to ask.
The answer is, as it so often is with AdWords, it depends.
By "budget of a keyword" I assume you mean the keyword's cost-per-click bid? My answer would be that you need to bid what provides you with the maximum results for the lowest or most profitable cost. If the traffic the keyword is providing is of good quality and is very profitable, then maybe you can afford to increase the bid--but only if you feel an increase in ad rank--say, improved positioning on the search results page or the ability to service more of the available traffic--will continue providing profitable results. Read Improving ad position and Ad Rank for a more detailed discussion of this topic.
As for your no clicks keywords--the answer there is a question for you. Are these keywords highly relevant to your goals and did you add them to your campaign because you thought they would drive quality traffic to your site? If the answer is yes, then I would ask if you've tested a variety of ad messaging to try to get some of the impressions you're getting to convert to clicks and website visits? Have you tried increasing your cost-per-click bid, to allow those keywords to achieve better ad positioning?
If the keywords were not part of your core strategy--if you were, for instance, just testing to see if they'd pull good traffic for you and they're not, then I'd probably delete them, if I were you.
There simply isn't any one-size-fits-all "rule of thumb" for advertising. What you need to go depends on your goals.
If you still have questions, please feel free to post again!
Google AdWords Top Contributor