[brweb]

Now... The mails are bigger then ever... like Yahoo Mail comes with 1GB, Gmail comes with 2.7GB and some others are also availabe...

But, it is possible that your friend would not using this service.
When you want to share files with friends, you cannot send attached files with mails... because if the file you want to share is bigger than the mail box your friend has, you cannot send it... So this services are offering with friends sharing...!