I'm all for it. I found it to be quite handy whenever I needed to do anything requiring me to sign up for any sort of membership (video or karaoke clubs for instance). Wasn't too keen on the fingerprinting at the time (which thankfully is no longer done) but all in all I thought it was convenient to have.
Btw, in case anyone doesn't know what they look like, below is an example (all personal info distorted naturally) taken from someone's weblog I found while doing a search for an example to post. (http://www.blogd.com/archives/000142.html)
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