Tracking parameters are the key to successful analysis of campaigns. Everything about tracking conversions, PPC keywords, and successfully associating purchases with the originating campaign depends on a landing page with a unique URL where visitors arrive when they click through. Because the URL must be unique, it's impossible to construct a different physical page for each campaign; you'll quickly need a very large number of pages. Instead, you can add tracking parameters to the end of the URL. The result looks something like this:
http://www.top5flicks.com/Action/signup/?bh_se=adwords&bh_camp=Action%20Rentals&bh_adg=Action%20Rentals&bh_head=one&bh_i=41
Everything after the question mark is called the query string. This string consists of five parameters; each parameter comes in two parts: a variable (the text on the left side of the equals sign) and a value (the text on the right side).
Here are the five parameters in the string (separated by an ampersand (&)):
bh_se=adwords
bh_camp=Action%20Rentals
bh_adg=Action%20Rentals
bh_head=one
bh_i=41
Explanation of the variables:
bh_se: the search engine the visitor came from. This is typically "adwords" (Google) or "panama" (Yahoo)
bh_camp: the name of the campaign
bh_adg: the Ad Group the Creative belongs to.
bh_head: the headline of the Creative
bh_i: used to identify similar or recreated Creatives.