Why Use the URL Builder?
Google’s URL Builder helps you add attribution parameters to URLs used in campaigns. You can generate campaign links using the URL Builder form at the bottom of this Google support page and then in Google Analytics > Acquisitions > Campaigns you will see visits to that page that are specifically from your marketing efforts related to the campaign.

Google's URL Builder helps you add attribution parameters to URLs used in campaigns. You can generate campaign links using the URL Builder form at the bottom of this Google dev page and then in Google Analytics > Acquisitions > Campaigns you will see visits to that page that are specifically from your marketing efforts related to the campaign. 

Photo: US National Archives

Here's How It Works

Instead of using this link in your marketing campaigns:

http://www.mysite.com/book/sample

You would generate and use this tracking link:

http://www.mysite.com/book/sample?utm_source=facebook&utm_medium=paid&utm_campaign=fall-sampler

See those extra goodies in your link? That is the campaign tracking code. In Google Analytics > Acquistion > Campaigns you will see “fall-sampler” and the number of sessions generated by people who clicked on that link from a “paid” piece of content, from the source “facebook.”

You would generate different parameters for using that link in Twitter, email newsletters, or banner ads, etc.

Parameters can be added manually or via the URL Builder form here. You can find similar tools by searching for “Google URL Builder.”