Can you make money out of Gmail?

With the GMail service, Google will effectively place ads in your email that will be relevant to what ever you are writing about.

If you write about astronomy or your holiday in the Bahamas, you could expect to see ads about telescopes or Bahamian hotels appearing side by side with your email.

If you are tempted to click on one of these ads money does move about - but at the moment it looks as though it will all go to Google (which is great if you've got some Google shares after the IPO).

What happens is that the advertiser gets charged for the click and Google bills them.

This is different from "normal" AdSense.

With "normal" AdSense, Google charges the advertiser but then shares this revenue with you if the ad that was clicked was on your site.

So for the time being it looks as though you can't make any money  from Gmail - but there's no reason why you shouldn't make money with AdSense on your own website.