Because ur forum gold is tied to ur ingame account. To receive forum gold you can either:

-Vote for gold ( Use the website's homepage, left down side ) 60 gold a day.
-Become a subscriber and u receive daily gold. 125 gold a day
-Win events
-Donate $

If u vote 1 day u get 60 gold this way u can allready purchase some items ( most are 1/2 gold each ). Most basic things dont cost gold: Reviving merc, tomes, potions etc.