This is different from the
Google Adsense Preview tool, (Internet explorer only sigh!) which will
have to work on already uploaded and hosted webpages and the ads will only show
if the page is already indexed by googlebot. But a
benefit is it allows you to view ads by regions like USA, India
etc., and that is how it works on the web too so it is more accurate. If you
see 10 ads on Adsense sandbox, Google preview for India for same url might show
1 ad only.
Another advantage is to find stop words -
those keywords which are sensitive in nature and adsense blocks ads on such
pages to reveal public service ads. So if for a keyword, sandbox shows no ads,
maybe it is a stopword for google and you should avoid it in your page content.
Combine these sandbox ads with the
Overture Bid tool and you have a winning
combination of high paying keyword
ads (or I might tell you later how). Make more money!