Today, Google Adsense updated their terms of service (TOS). The announcement was posted here and you will also see a message when you login to your adsense account with the updated TOS. It has been almost 2 years since the last update. The last significant update was made in November 2005.

So what are the most significant changes?

1) Publishers now need to add a new privacy policy to their website disclosing information about ad cookies to visitors.

2) You can show Google ads on error 404 pages and registration pages as the following line is now deleted from the TOS:

[Deleted - Prohibited Uses] (You shall not) display any Ad(s), Link(s), or Referral Button(s) on any error page, on any registration or “thank you” page (e.g., a page that thanks a user after he/she has registered with the applicable Web site), on any chat page, in any email*.

*this may be a hint that AdSense for Email program is in the pipeline!

3) You can place Adsense associated with multiple AdSense accounts on the same page.

4) You can place AdSense for Search box on pages that have no content.

5) AdSense Referral products (like Firefox, Google Pack, etc) can be placed on pages that contain no extra content.

6) If you are participating in any of the beta AdSense features (like AdSense for RSS Feeds), you should not talk about them on your blog.

7) You can have ads from other contextual advertising networks together with AdSense on the same page. Yes!

8) If your AdSense account is inactivated, Google may donate your earnings to charity.

Note: You need to accept this new TOS before May 25, 2008 or your account will be deactivated.

If you like, you can download this side-by-side comparison which i got over at Digital Inspiration.

Disclaimer: That above notes are based on my understanding of the new TOS and my readings over at Digital Inspiration who did a great job of capturing the main changes of the new policy changes. I may have misinterpreted some points so please consult your AdSense if you need to be sure on any of the above points.