

Track conversions across multiple domains (using third party cookies) - paraschopra
http://visualwebsiteoptimizer.com/split-testing-blog/easiest-way-to-track-conversions-across-multiple-domains-using-third-party-cookies/

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paraschopra
If you need technical details on third party cookies and other interesting
(cross-domain stuff) here is a presentation that I referred to:
[http://www.slideshare.net/SlexAxton/breaking-the-cross-
domai...](http://www.slideshare.net/SlexAxton/breaking-the-cross-domain-
barrier)

Essentially, you load a different domain in IFRAME which sets the cookie. IE
requires you to set a P3P header for it to work properly. And Safari required
the visitor to have visited the website before. To get across this, you first
load a different domain in IFRAME and then have form submit to that domain
(with target being IFRAME). (IE7 opens a new window in this case since it
doesn't recognize target attribute). Crazy cross-browser issues. I wish there
were a simpler way of doing cross-domain tracking.

~~~
rumpelstiltskin
Are you saying this was how things were done before? Or this is how things are
done now?

P.S. Also, does your software's MVT optimize itself like genetify -
[http://www.shoemoney.com/2010/03/03/split-testing-with-a-
gen...](http://www.shoemoney.com/2010/03/03/split-testing-with-a-genetic-
algorithm/)

~~~
paraschopra
This is a new feature that we have released today! I'm excited about this
because it solves pain-point of a lot of our users.

No, VWO doesn't dynamically optimize because statistics become s really
complicated once you try to model such optimization. As far as I know Genetify
(or any other tool out there) doesn't have a statistically valid method of
optimizing the test (while it is running).

The math required to do such optimization while maintaining statistical
validity is beyond me, at the moment. (Though I am actively researching on
this front. Any pointers/links will be appreciated)

~~~
rumpelstiltskin
So no more iframing etc?

Genetify is open source - <http://wiki.github.com/gregdingle/genetify/> \- you
can have your programmer go through it for the algorithm. That'd be a good
starting point.

Statistically valid optimization would be a HUGE plus. Enough for me to pay
for VWO instead of using genetify.

~~~
paraschopra
Genetify doesn't have a statistically valid algorithm so no point looking at
its source. Moreover, there are some basic optimization features already built
into VWO: [http://visualwebsiteoptimizer.com/split-testing-blog/why-
ab-...](http://visualwebsiteoptimizer.com/split-testing-blog/why-ab-testing-
is-truly-risk-free-even-when-every-lost-sale-matters/)

Third party cookies (via IFRAME) is a choice, it isn't enabled by default for
all tests.

~~~
rumpelstiltskin
Ahh I see. Cool.

