There are various online and client tools to manage the efficient
purchasing of keywords. e.g. www.atlasonepoint.com or
www.apexpacific.com

I haven't been able to find software that allows you to manage the
buying of keywords through to management of the adverts accociated
with those keywords. This is relevant when you are trying to manage
lots of customer campaigns and want to minimise the keying of data.

a successful answer would provide an example of a provider where you
could manage the purchase of keywords through to the management of
individual campaigns and adgroups, where you were able to edit the
adverts too

Greetings Dear cbpjf-ga 

I have located the service you are in need of.  

Quote

Salesforce.com Inc. this week added an online advertising management
service to its hosted CRM system. San Francisco-based Salesforce.com
says the new service can help customers more easily manage marketing
campaigns on Google Inc.'s search engine.

The new Salesforce for Google AdWords CRM service tightly integrates
the processes connected with creating, managing and benchmarking
marketing campaigns on the Google search engine, said Kendall Collins,
Salesforce.com's vice president of product marketing.

All of the processes can now be handled directly through the
Salesforce.com interface, which is linked to Google's Web site,
Collins said.

In addition, Collins said the new service lets customers purchase
keywords and create advertising text through the Salesforce.com
interface. It then correlates sales leads with ad clicks. A customer
can use the service to measure which advertisements and keywords are
delivering results, allowing for more intelligent spending of
advertising dollars, Collins said.
Unquote

For complete text please link to :

http://www.computerworld.com/action/article.do?command=viewArticleBasic&articleId=9002827&source=rss_topic120


2. While looking around for your requirement ? I chanced on this on
pay per click advertisement.

Please have look at this site, very comprehensive one.

http://www.opentracker.net/en/articles/pay-per-click-ppc.jsp

hope the above meets your requirement


regards
jadayu