Since i got my GMail account few years ago, i never switched back to my previous YahooMail. I used YahooMail only for Yahoo Messenger and it's not my primary email again. I just switch to GMail and i don't think i will move out from GMail. It's a great product by Google and they keep improving it bit by bit by adding more and more tweaks via Google Labs.
But not everyone have their own GMail account and sometimes i wondered why? Is it because they already have too much messages on their inbox? Or they have too much contact to informed? Google has created a new campaign called Email Intervention to help users migrate their friends who hasn't use GMail. Simply follow three steps to invite and personalize it to your friends.
I think it's a good campaign, but i believe they could do better if they use their first video about GMail. I think it's still as amazing even though it has lived for years.