Dopplr and confirmation emails - Micro case study

Most Web 2.0 sites utilize some form of email confirmation mechanism where an activation email with a special embedded code is sent to a newly registered user. This user then checks his/her email and clicks on the link to activate their account.

Depending on the site's policy, the registration data of the newly registered user may be deleted if the user doesn't confirm their email account within a specified period of time. Some websites delete such data within 24 hours.

A few days ago, Mark Atwood, a good friend of mine sent me an invite to Dopplr, a Web 2.0 site that tracks people who travel frequently. I registered, however I forgot to activate my account. To my pleasant surprise, I today received an email from them regarding my Dopplr journal in which they politely reminded me that I haven't confirmed my account. Edited contents of the email follow:

Ever since you joined Dopplr, we haven't checked with you that this is your correct email address. Would you mind telling us that this is the address you use with Dopplr by following this link?

http://www.dopplr.com/account/confirm_email/XXXXXXX

There has been 1 thing reported in your journal since Tuesday April 29th. 

I happily confirmed my email this time and Dopplr gets to keep me as a new user. Had they deleted my registration data, I probably wouldn't have cared to re-register.