The Power of Parameters

Several times I've emphatically stated on this blog that you can't nest one parameter inside another. It's time to eat my words.

What's a parameter? How is it useful? And why are they nesting? (I'm forcibly restraining myself from making a bad pun here.)

A parameter, also called dynamic text in adCenter, is a string value that's not resolved until runtime. That's how developers define it. For the rest of us, it's a bit of text that isn't finally defined until your ad is served.

Dynamic text allows you to do things
with your ads otherwise impossible.
They're a powerful tool under-utilized
by most advertisers.

Let's say you're bidding on the keyword "award winning widgets" for exact, phrase, and broad match types. Your destination URL is:

  HTTP://www.example.com/LandingPage.html?matchtype={MatchType}

Just-In-Time Definition

The value of MatchType is dynamic—it isn't determined until your ad is served. It might be an exact match, a phrase match, or a broad match depending upon the visitor's query that triggered the ad. It's basically a placeholder for a value that's determined the moment your ad is published. If the query was "award winning widgets," the value of MatchType would be e (for exact); if the query was "winning widgets," the value would be p (for phrase); if the query was "widgets," the value would be b (for broad). Tracking the number of conversions associated with each match type for a single keyword—and the cost of those clicks—helps determine your return on investment for a particular keyword at a granular level. Is exact match worth more to you than broad match? If so, how much can you afford to bid on exact match and remain profitable? The answers to those questions will provide your search engine advertising with a competitive edge.

Continuing with our example, a hypothetical visitor uses the search phrase "winning widgets" and clicks on your finely crafted, highly relevant ad. The URL they arrive at will be:

  HTTP://www.example.com/LandingPage.html?matchtype=p

Your web analytics should be able to track conversions for all visitors who landed on this URL. Unfortunately, that's less than helpful. You're missing a critical piece of information. What's the keyword? You need to add another piece of dynamic text to your ad's destination URL to look like this:

  HTTP://www.example.com/LandingPage.html?keyword={Keyword}&matchtype={MatchType}

This time your visitor arrives at the following URL:

  HTTP://www.example.com/LandingPage.html?keyword=award%20winning%20widgets&matchtype=p

You may be wondering at the addition of the %20 between keywords. Internet protocol doesn't allow blank spaces in a URL so it encodes them as %20 instead. Microsoft's adCenter Analytics (currently in beta testing)  is capable of decoding this URL and reconstructing the keyword as "award winning widgets." Other analytic solutions may not.

Here's the full list of dynamic keywords available in adCenter:

  {Keyword}
  {MatchType}
  {QueryString}
  {OrderItemID}
  {AdID}
  {Param1}
  {Param2}
  {Param3}

There are two types of dynamic text—those defined by adCenter and those defined by you, the advertiser. Param1, Param2, and Param3 (param is short for parameter) can be defined by the advertiser, within certain limitations. Param1 has a 1,022 character limit while Param2 and Param3 have limits of 70 characters each.

Nesting Parameters

Another of those limitations once was that you couldn't insert one dynamic value (Keyword, for example) inside another (Param1, typically). Which brings us finally to my diet of words.

If you're building a unique destination URL for each keyword, it makes perfect sense to use Param1. Destination URLs can get pretty long and Param1 accommodates the longest string—1,022 characters. You might want to dynamically add the value of your keyword or match type to your destination URL, or the exact query typed by your visitor. You might think you could use the following value for Param1:

  HTTP://www.example.com/LandingPage.html?keyword={Keyword}&matchtype={MatchType}&querystring={QueryString}

You might think that but in the past, you would have been wrong. In the past, you couldn't nest one dynamic value inside another. Now you can but there's a caveat.

Although you can insert the dynamic values defined by adCenter (Keyword, MatchType, QueryString, OrderItemID, and AdID) into a dynamic value defined by you (Param1, Param2, and Param3), you can't insert one user-defined value into another. In other words, you can't insert Param2 into Param1. The following won't work as a value for Param1:

  HTTP://www.example.com/LandingPage.html?UserDefinedValue={Param2}

You can't because you would create a circular reference—one dynamic value looking up another that references the first in an endless loop. Your keyword will be rejected during adCenter's editorial review process.

Dynamic text allows you to do things with your ads otherwise impossible. They provide a means of transmitting data between your adCenter campaigns and your web analytics solution as well as building ads on-the-fly. They're a powerful tool under-utilized by most advertisers. And they can be nested one inside another.

Acknowledgements

I'd like to thank Jason Dorsey, adCenter Technical Support Analyst, for his help in vetting this article, and the folks at Efficient Frontier who first challenged my assumptions. Any errors are entirely my own.

You can find more information about dynamic text in adCenter's help files and previous posts.

  Painless Parameters: dynamic text in adCenter
  Dynamic Keyword Insertion in adCenter
  Conversion Tracking: Part 1
  Conversion Tracking Part 2: Installing the Script
  Conversion Tracking Part 3: Gathering Data
  Conversion Tracking Part 4: Actionable Intelligence