My plugin for WordPress already uses the new tracking code, making switching one of the easiest jobs ever. It also allows for a few other tricks like tracking image search queries and outbound clicks, and will be using events as soon as they're out of beta.

Would astrack.js (http://www.seobook.com/archives/001370.shtml) work with ga.js?

It seems it won't, because at its core astrack.js calls urchinTracker('/asclick');

Is there AdSense Google Analytics tracking script available that is compatible with ga.js?

hold on, i swear it says in GA that you can have both implementations on a site, just not on the same page.. ?

Can you provide some clarity on using the new ga.js code in a "3rd party cart" situation?

There are some differences in the approach suggested by the "Migration Guide" and the Google Analytics help page on the subject.

For the GATC, the Migration Guide (pg. 9) recommends adding:
pageTracker._setDomainName("none");
pageTracker._setAllowLinker(true);

while the Help page "separate store site" example suggests:
pageTracker._setDomainName("mystore.com");

My guess is that the PDF has the correct code. Can you confirm?

For the link to the 3rd party cart, again 2 methods are described.

The Migration Guide:
<a href="http://newsite.com/test.html" onclick="pageTracker._link('http://newsite.com/test.html'); return false;">click me</a>

The Help page:
<script type="text/javascript">
document.write(
'<a href="javascript:pageTracker._link (\'https://www.securecart.com/?store=parameters\');">Purchase Now</a>'
);
</script>
<noscript>
<a href="https://www.securecart.com/? store=parameters">Purchase Now</a>
</noscript>

Here my guess is that the Help file is correct. Again: Can you confirm the "correct way?"

Thank you for such a though-provoking post!

Is there any place I can find some details about HOW Google tracks off-site clicks automatically?

I'm interested in the technical implementation--the method Google is using to track off-site clicks.

@Adam:

You can indeed use both versions of the script on a single site while it's transitioning (although it's not a great idea). I would definitely avoid using both on a single page.

@Dennis:

Any code that contains the urchinTracker() function will not be compatible with ga.js. I don't know if anyone has had a chance to update it yet. I'm sure it won't be long.

@David:

Using ga.js with a third-party cart is just as complex as using urchin.js. Usually, you'll want to set pageTracker._setDomainName("none"); but this will not be the case for all situations, including if you have subdomains. The only way to make sure you are integrating Ecommerce correctly is to have someone look over your Google Analytics setup in a one-on-one environment, as many situations require specific, customized instructions.

The Code which conflicts with ga.js is not functional.. Additionally, Even ecommerce setup for Google analytics does not give accurate reporting, due to deletion of cookies by user etc.. which is about 40% high..

I have another question, about the Google Analytics code, it seems to be reporting null visitors, which is impossible, Has urchin.js stop working...

@ Analytics India

Urchin.js should still function correctly. It sounds like you may have a problem with your installation, and I recommend you get someone to take a look at it.

When upgrading from the old GATC(urchin.js) to the new GATC(ga.js), is there any loss of reporting data collected under the old GATC implementation?

@Jim: urchin.js and ga.js use the same cookies. When you're making the switch, as long as none of your pages go live without either tracking code, you should be fine.