Azathrim said:ActiveChars is the only indication we have of number of players on a realm. It's not very good though, as it's just the number of characters logged on in the last week or so. So, if I log on all 16 characters on my two accounts in an hour, it increases the number greatly. If I stick to main+buffbot it's only 2 active characters.
However, it is a slightly indication - nothing more.
Regarding this way of measuring the population. On all characters the /played is kept track of. Why not use it to see how many actual hours a realm is populated by actual accounts. I am not saying it should be the only way of deciding how active a realm are but it could a part of the way to calculate population bonuses.
/Otho

(+ other random name calling)