clear gifs: a tracking method

[jeex]

i was reading over a privacy policy for a certain web service today and i came upon something interesting.. i hardly ever read privacy policies, but what i found was kinda neat..

Clear Gifs
Clear gifs are tiny graphics with a unique identifier, similar in function to cookies, and are used to track the online movements of Web users. The main difference between the two is that clear gifs are invisible on the page and are much smaller, about the size of the period at the end of this sentence. Clear gifs are not tied to users' personally identifiable information.



We also use clear gifs in our HTML-based emails to let us know which emails have been opened by the recipients. This allows us to gauge the effectiveness of certain communications and the effectiveness of our marketing campaigns. If users would like to opt-out of these emails, please see the Opt-out section.

the whole part about seeing whether or not an email has been read was the most interesting part to me.

as most of you know, its kind of hard to know if someone has read your email (unless you have aol), but these 'clear gifs' would make that possible..

[tgpo]

That's why I turned off the option of my e-mail program to show images. Spammers use it to know which address are live.

[rallynavvie]

Yes indeed, I've known of this trick for a while. Disabling images in your email should be a no-brainer as it will show the dummy image as an attachment should you choose to open it. Of course I'm still old-fashioned and believe email should just be text with pictures and all that as attachments anyway

[housepig]

okay, maybe I'm not grasping something simple - how would recieving a mail with a clear gif communicate to the sender that I had read it?

[tgpo]

They send specific images to specific e-mail address. Thus if the image is loaded they confirm that the person that image was sent to opened it.

For example:

Send email to Baldrick with embeded image CAT1.gif
Send email to jeex with embeded image CAT2.gif
Send email to Gees with embeded image CAT3.gif

I look at the logs and image CAT2.gif has been loaded, thus I know that my e-mail address for jeex is live.

[Capmaster]

That's damned sneaky. I've read about these a few years ago. It's another way our privacy is being invaded by these slimeballs. They think that by shoving this stuff down our throat we're going to give in and buy it? I'll do the opposite. They need to get an honest job and leave us alone...... *RANT MODE OFF*

[housepig]

They send specific images to specific e-mail address. Thus if the image is loaded they confirm that the person that image was sent to opened it.

For example:

Send email to Baldrick with embeded image CAT1.gif
Send email to jeex with embeded image CAT2.gif
Send email to Gees with embeded image CAT3.gif

I look at the logs and image CAT2.gif has been loaded, thus I know that my e-mail address for jeex is live.

"if the image is loaded..."

so the image isn't "embedded" per se, it's an <img> link in the HTML??