This method is suitable if there is no opportunity to amend the code of a site, but if you have access to the site's files, it is better to use another of the proposed plug, since this gives way to collect statistics plugins.
If You using tracking URL protection service from click fraud, You accept additional agreement to use the service
  1. Login in to Campaign Managment Google AdWords
  2. Select menu item Settings > Account Settings
  3. Insert in to "Tracking template" value https://click.siuc.biz/gw/?url={lpurl}&keyword={keyword}&placement={placement}&utm_campaign={campaignid}&siuc=<unic>
  4. Enable "Auto-tagging"

<unic> - Need replace to unique identifier site in system