saving session variables for postback on conversion

[somescreeenname]

Hi there, I'm trying to get a postback working upon customer conversions when they were referred to my Magento site by HasOffers. The source then requires one/some of the variables it sent in the referral back upon a successful conversion (in this case, when the customer reaches the "thanks for paying" page).

HasOffers related documentation is visible at http://support.hasoffers.com/hc/en-us/articles/203338487-Postback-tracking

My question: how can I store the information passed in by HasOffers? It appears to come in in GET params; am I lucky enough that Magento is smart enough to store unrecognized GET params in the session? Am I going to have to hack it to do so and then get them back out for the postback on the success page? Or is there something else I haven't thought of?

We're working with another party with HasOffers which requires the use of the postback, so the (theoretically) simpler tracking pixel solution will not work in this case.

[somescreeenname]

I guarantee this is a problem that a thousand people have had, and the "documentation" and what comes back from web searches is ... lacking, to say the least.

We're flailing our way through this and hope to open-source a generic affiliate postback module (or whatever it's called in Magento) once done, if our bosses are cool with it. If so, I'll link to the band-aid in this thread.