Google announced a few weeks ago that it will use the load times of your destination urls as another factor in the Quality Score for your landing page. The landing page quality score impacts the minimum bid for each of your keywords.
According to Google, "you can see a keyword's load time grade on the Keyword Analysis Page.
- If your keyword is graded This page loads slowly, your landing page quality and Quality Score will be negatively affected.
- If your keyword is graded No problems found, your landing page quality and Quality Score will not be affected. The one exception is if your keyword is graded No problems found and marked Load time is faster than the average in your server's geographic region. In this case, your landing page quality and Quality Score may be positively affected."
This is a good idea from Google. Most searchers will click the "back" button if your destination page takes too long to load anyway, so this "rating" may help you identify issues with load times that have been costing you money.
Search Engine Marketing Firm