July 27th, 2007 | Published in Gmail (Google Mail)
So how does this help you? Let's say you get lots of mail about Xena (you know, the Warrior Princess), and you also get lots of mail from friends. In most mail applications, you could put all messages about Xena in a "Xena" folder and all mail from friends in a "Friends" folder. But when a friend sends you a note about Xena -- well, you could make "Xena" a subfolder of "Friends," which doesn't totally make sense. You could make "Friends" a subfolder of "Xena?" Or maybe make a copy of the mail and put it into both? Sure, if you want to keep track of both, take up twice the space, and forget to delete one if you ever delete the other. Blah!
Now let's say you have Gmail labels. If you get a Xena mail from a friend, just apply the label "Xena" and the label "Friends". Now you can find it in "Xena," you can find it in "Friends" -- and you only have to keep track of one thing.
If you don't get the Xena thing, replace "Xena" with "Buffy". If you still don't get it, replace it with "Britney" or, if all else fails, replace it with "Work." And there you have it.