Integration with Gmail...
For people that spend most of the time on desktop or laptop, there is no urgent need to use smartphone for email notifications, since there is already a browser with big screen in from of them.
There was a plugin notifier for Firefox that could do this,
but it is not supported anymore, since "Constant Gmail changes are making this no longer fun"...
In Chrome browser this is one of embedded features,
and Chrome has quick auto-updates on every start,
so updates are transparent anyway.
Chrome is becoming for Firefox almost like IE for Netscape at the time of browser wars...
Anyway, this nice feature is not enabled by default,
and here are the steps:
Desktop notifications in Chrome - Gmail Help
You'll be able to turn Chat notifications on or off, and can also choose to turn email notifications off, receive notifications for all incoming email, or only those Gmail marks 'important'.