Does group bonus only apply if...

[Gustoo]

You get more overall exp with grouping. And the 6th person is entirely free.

Basically get a little more than half normal exp in a duo. Duos are good when they make you amazing.

[Aesop]

Tassador is just a shitty forum troll, ignore him

[Tewaz]

Exp in a full group on red absolutely flies and I think the guesses at the math have been a bit under what it works out to.

I think exp works like this.

100 xp flat on red becomes 150xp every time.

On blue, a 100 xp mob killed by a group of six doesn't give 16.67 xp per mob, because the group bonus increases it. Something like 100/6 + 4.3 xp (some amount of group bonus xp). This mechanic existed on live and was huge on EQMac since you could engage it while out of range: 4 people soloing in a zone would all group up and spread out and get bonus xp.

On red, this xp bonus is increased by 40% per group member and I believe the formula becomes:

100xp mob increased to 150 xp then killed by 6 people = 25 xp plus the group bonus multiplied by 290% for a full group.

Blue: 100xp mob killed by group of six = 100xp/6 + theoretical bonus of 4.3xp = 21 xp per group member.
Red: Same 100xp mob killed by group of six = 150xp/6 + theoretical bonus of 4.3xp x 290% group bonus = 37.5 xp per mob.

When I leveled 2 years ago, we would have multiple group members go afk from time to time and it was better (so we thought) to keep them in the group instead of them camping out for extended (30+ minute) periods.