Reasons for Using Fetch as Googlebot
1- You are using rich media files or flash and have doubts that Google may not crawl your web pages effectively.
2- Hacked pages can be identified easily with the help of this tool.
3- If you want to check the crawlability of your site then this is the best tool to use.
Fetch as Googlebot shows the 4 different parameters:-
URL
Date
Googlebot Type
Download Time
An example is given below:-
Remember, you can only use 500 fetch request per week, per Webmasters Tools.
Also See:-
Site Analysis Tools
Free Seo Tools
Google Moonshot Changes
Seo Factors That Have the Biggest Impact on Rankings
Utilizing Tf-Idf Score to Increase Site Rankings