I think I was destined for a career in online marketing. While most kids were learning to say "mommy" or "daddy," my parents will vouch for the fact that my first word was "cookie."  I just didn't realize I was talking about Internet personalization until many years later.  Sorry, Mother's ; )

There has been a lot of talk about cookies this year.  In April, Jupiter Research released an interesting study on cookie deletion that sparked a number of aftershocks from the online marketing community.  Many marketers were buying into the myth of cookie-based customer profiling, and the notion of a 40% monthly cookie deletion rate seemed to thwart their plans for personalization.  Well, let's be candid about this: cookie-based visitor profiling has never been accurate.  If I log onto your site while I am at work, but I do not complete a purchase until I use my home computer later that night, am I two different people?  What if my friend uses my computer to make a purchase...are we the same person?  What if I use my PDA?  My TV?  What if I shop online but I place my order over the phone...are you asking me for my online promotional code?  Are you doing the same for my catalog orders?  What if I originally reach your site through a PPC advertisement before returning via an email promotion?  Should you count me as a PPC conversion, an email conversion, or a deferred email conversion; or should you increment each acquisition method (either equally or via a weighted formula) that led to my purchase?

Now, we get to the subject of cookie longevity.  I think we all understand that persistent cookies are being deleted by consumers with higher frequency than we originally expected.  But how and why are they being deleted?  Not all cookies are manually selected for deletion by the end user.  Some of these third-party cookies (written in a domain other than that of the visited site) are automatically selected for deletion by the consumer's chosen spyware removal tool.  Thus, he/she is not taking an active part in the eleminiation of tracking files.  Still, many people are manually deleting these "plants" and some savvy surfers are altering their browser settings to automatically block third-party cookies from ever reaching their computer.  Newer browsers are making this choice easier and easier for consumers.  Some browsers give the user the option of allowing session cookies (while applying restrictions to persistent cookies) in order to enable shopping cart processes and other sequential must-haves.  However, how many visitors truly understand all of these nuances?

So, have you completely lost faith in cookies yet?  Well, I would be lying if I claimed that my second word was "log-in," but it would have been a natural follow-up to "cookie."  Providing a log-in mechanism on your site(s) can help you skirt around the aforementioned challenges.  Once I log in to your site, you have a relatively credible idea of who I am and you can build a usable profile of my behaviors and preferences.  However, this is not a foolproof answer.  Many sites offer a log-in option without requiring visitors to use it. (I'd love to see a study that delves into the proportions of log-ins to anonymous sessions.)  Also, keep in mind that some visitors will use your site so infrequently that they will forget both their log-in credentials and their corresponding hints (security question, former email address, etc).  If your password recovery system does not ask the right questions, some of your visitors will create multiple log-ins during the course of their relationship with you.

If your company is truly devoted to the concept of customer profiling, then you must invest the necessary resources to capture a gestalt view of each person.  Their email click-throughs, phone calls, offline purchases, customer service live chats, affiliate referrals, etc also need to be tracked, updated and included in the profile.  If your current vendors are not able to integrate with each other for whole-view analysis, then consider shopping around.  There is a technology curve in every online marketing industry, and the leading vendors are as interested in system integration as you are.