Mit "tagline" werden im Werbesprech meist die Zusätze zu Marken bezeichnet, z.B. Nikes "just do it" und abertausend andere. Auch in CVs werden inzwischen wohl taglines eingesetzt, da es ja darum geht, sich selbst zu vermarkten. Siehe auch Link.

siehe:
http://www.howtoattractcustomers.com/ar-email1.shtml

The last thing all of your e-mails should have is your E-mail signature tag. You can automatically add a "tag line" at the end of each e-mail you send. The tag line can name your web site address, your phone number, USP, etc.

This is a very powerful way to create traffic to your web site because every time you submit an e-mail, the message will be there. Once it's set up, it's automatic. You don't even have to think about it. Your message can be anything you want.

For example: you can simply remind the reader to visit your web site for updated information. You can also invite the reader to enter your contest located at your web site; download information from your site, or see the top ten listing of whichever subject you choose. The possibilities are limited only by your imagination.