Google has launched a new feature to its AdWords program which aims to improve the relevancy of their AdWords product. The new role out will start out being tested on broad match ads which appear on Google.com. ...

New! Improved targeting for your ads.
Recent improvements to AdWords ad quality will help Google show the most relevant ads to the most targeted audience possible.

How is Ad Relevance Determined?

Our ad quality improvements will help us be more precise in identifying the most relevant ads for a particular query, which may mean more clicks for some ads and fewer clicks for others.

For example, an advertiser specializing in Alaskan cruises may have selected cruises (broad-matched) for their campaign. Previously, this keyword may have been disabled due to poor performance on more popular queries such as Hawaiian cruises. Instead of disabling all broad match variations of cruises, we will now show this ad for specific query variations that are more relevant to the ad, such as Alaskan cruises.

Which ads or keywords will be affected by these relevance changes?

Recent improvements to promote ad relevance within the AdWords system will apply to advertisers in all countries and all languages. While these changes will initially only affect broad-matched keywords for ads shown on Google.com, future improvements will include other keyword matching options and Google Network sites and products.

more questions (with many repeat answers) at https://adwords.google.com/support/bin/topic.py?topic=131&hl=en_US

hat tip to Optimize Online @ Search Engine Watch Forums