Many marketers are asking me about personalized marketing, which you should expect to see more and more of in the next few years. We've already seen behavioral targeting in display ads and personalized search, and we'll see more personalized advertising emerge. But are we marketers just assuming that users will allow all this personalized marketing in? What if they clean their cookies regularly? Will that prevent those users from being exposed to personalized ads?

These are good questions. To answer them, we need to understand a bit about how personalization on the Web works. You can expect that any personalized approach depends on at least one of three basic techniques:

• Cookies. This is the most common approach, and it can be interfered with when people "clean out" their cookies (by deleting them).
• User IDs. This is an increasingly popular approach, where users have registered with a Web site, so that Web site can personalize whenever they are signed in. Deleting cookies can somewhat affect this approach, because users would surf anonymously until they signed in again.
• IP detection. By examining the network location of a user, Web sites can determine your geographic location and possibly even the company whose location you are working from.

So, how does cleaning cookies affect these types of personalization techniques?

Behavioral targeting generally depends on a combination of cookies and IP detection. If users are blocking cookies (ensuring they are never set), that would affect behavioral targeting a great deal. If they are cleaning cookies, it would erase the memory that behavioral targeting depends on, but behavioral targeting could work in between cleanings.

Search personalization generally depends on User IDs and IP detection, but uses cookies to remember the User IDs so that users are automatically signed in. Cleaning cookies means that personalized search would not work until users signed in again. Because the act of searching itself does not require signing in, users might not sign in until they want to see their Gmail or their Yahoo! Finance page.

Personalization can use many different methods, of which cookies enable just some. Personalized marketing is coming, even for those who clean or even block cookies.

Mike Moran