Cookie Deletion: How It Affects Media Buyers

If you’re an online marketer, you’re sure to have heard the buzz about cookie deletion. Jupiter Research, among others, finds Internet users delete cookies more frequently than they used to, and certainly more than anyone suspected.

Some say it’s because of anti-spyware programs that wrongfully identify cookies as security threats and encourage users to delete them. Others presume last year’s release of the Windows XP Service Pack 2 is to blame, as it forces users to make a decision about deleting cookies they weren’t prompted to make before. Consumers’ misguided belief that cookies invade their privacy could also be a factor.

Whatever the case, analysts say the trend stands to cause serious problems for online advertisers.

Like many media buyers, you probably wonder why. You’ve heard talk of cookies. You know they’re used for Web measurement. But unless you’re heavily involved in campaign management, work next to a campaign analyst, or eavesdrop on your agency’s tech team, your cookie knowledge probably stops there.

Countless buyers and online strategists haven’t participated (or been particularly interested) in Internet technology or back-end campaign operations, cookies included. In this case, you should cozy up to the tech experts. Understanding the cookie’s purpose is essential, because deletion has a direct effect on the success of all online campaigns.

The Cookie’s Purpose

Technically, a cookie is a small string of text stored on a user’s computer by a Web site server. It will later be retrieved or referenced by the user’s Web browser. The cookie contains a unique code that allows the site publisher to anonymously identify the user and, depending on the type of cookie (i.e., a temporary “session” cookie or a more permanent “persistent” cookie), track her as she interacts with the site. The code is usually assigned to the user on her first site visit and is referenced each time she returns until the cookie is either deleted or expires.

Cookies generally have four purposes:

  • Measure site and campaign traffic.

  • Measure a campaign’s effectiveness by tracking user actions after ad exposure.
  • Identify audience traffic patterns and aid in targeted ad delivery.
  • Cap ad impression delivery.

Deletion’s Fallout

Considering these purposes, you can start to understand the problem. When cookies are deleted, publishers can’t accurately measure site traffic. Media buyers can’t make informed decisions about which sites to utilize or estimate their audience reach. If a cookie is deleted between the time a consumer sees an ad and when he makes a purchase, you’ll also have difficulty determining the buy’s origin and gauging the ad placement’s effectiveness.

There are also long-term repercussions. Without frequency capping, marketers may unknowingly run campaigns that create negative impressions of their clients’ brands.

Disturbing as these consequences may sound, cookie deletion likely won’t be the end of online advertising. There are several things media buyers and marketers can do to improve the situation, in fact.

Two Solutions

The first is education. Know what percentage of your audience deletes cookies so you can better analyze your campaigns. Media buyers can no longer assume the statistics they get are precise, whether they originate from a third-party measurement firm or their own proprietary software. Jupiter Research recommends site publishers spend more time scrutinizing their users’ actions and pass the information on to marketers for comparison with their own findings.

Marketers can also look to alternative measurement solutions, such as those offered by United Virtualities. Its Persistent Identification Element (PIE) delivers Flash MX files to users along with traditional cookies. The result is the restoration of deleted cookies, along with added measurement capabilities; Flash files are more difficult to delete than cookies and are therefore more likely to remain where they’re placed.

The cookie deletion dilemma is still fairly new. Additional solutions are likely headed our way. In the meantime, this is one technology issue marketers must watch. Cookies are essential to our industry. Unless we’re prepared, this one’s sure to come back to bite us.

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