tracking PPC keywords with optins

[Wicketywick]

Un my site, I offer a report to download. My optins then receive e-mails through an autoresponder and eventually some buy.

Ultimately, I would like to know which keyword brought the customer.

Anybody know how I can include the Adwords keyword in the optin form - hidden input field?

[still]

Guess you can pass the Adwords keyword from the Ad's destination URL via a dynamic parameter then store it for that session in a cookie.

e.g. your destination url could be http://www.example.com/landing.html?kw={keyword}