Since Google Drive launched in April, millions of people have started 
using Drive to keep, create and share files. Starting today, it’s even 
easier to share with others: you can insert files from Drive directly 
into an email without leaving your Gmail. 

Have you ever tried to attach a file to an email only to find out it's too large to send? Now with Drive, you can insert files 
up to 10GB
 -- 400 times larger than what you can send as a traditional attachment.
 Also, because you’re sending a file stored in the cloud, all your 
recipients will have access to the same, most-up-to-dat...
 read more : -> http://gmailblog.blogspot.in/2012/11/gmail-and-drive-new-way-to-send-files.html