Tracking from keywords to clicks, from clicks to actions (opt-in, sale, ...).
Google Conversion tracking:
Login into Google AdWords, click on "Conversion Tracking"
in the "Campaign Management" tab.
Click on "Customized Conversion Tracking", then on
"Start Tracking".
Select "Purchase/Sale", select language, and http
or https - then copy/paste html into your thankyou web page at
the bottom (right before the </body></html> tags).
Now in Google report you see two more columns - Conversion rate
and Cost per Conversion