An OG Gamertag is an original gamertag,

Original -
1. Preceding all others in time; first.
2. Not derived from something else; fresh and unusual:
3. the first and genuine form of something, from which others are derived


Many people believe it is one worded but does not have to be, those are especially considered "og"

OG Gamertags normally do not have numbers, are short in characters and are one-two words that are not very commonly seen. Ex - "Reflex" "Fruit Snacks" "Black Ops"

How often do you see tags like that? Not often. Many are seen as "vReflexxZ" "Fru1t Sn4ckz" "Black Opz123"

Basically because people want to be original as "Reflex" but these are already taken so they add #'s and extra letters.

Why are they so popular all of a sudden?

If you check the news room you'll see a topic about Major Nelson releasing dead gamertags that have not been used in long periods of time and are silver. So people have been sitting around the past few days trying to get these "OG dead tags" and it is really something special to have one. Some have been taken and dead for up to 10 years. So of course people are going to want to show off to the TTG community, alot of people really do admire OG tags.


Hope that helped,

Seductive.

Resources - Dictionary.com, E-thugs, being an original gamertag owner.