It is very important to know if you are wasting money with your Google Adwords account or if you earn money.
Google delivers an excellent conversion tracking system for free.

How to set up Google conversion tracking?
(Time for setup: 5 minutes)

Open your Google Adwords account and click on "Conversion Tracking".

Next click on 'Create new action'.

Name your action and set the Revenue for your action:

Describe where action is completed.

Customize the tracking indicator.

Finally click on the button 'Save Action & Get Code'

On the next page you get your conversion code.

Copy your conversion code into your html code of your "Thank you for your purchase"-page.

You can create similar page codes for leads, sign ups, of views of key page.

Please note:
Google will track sales only within 30 days. Additionally the cookies must still be present during the purchase.