We have a weekly lottery. 50% of each ticket purchase goes toward the pot while the other 50% goes toward the guild to maintain the PvP server, go toward contest prizes, convert to influence, whatever. So if someone puts in 5 gold, 2.5 gold goes to the pot, 2.5 gold goes to the guild bank. Each ticket is worth 1 gold.
We've given out precursors before as a reward for stuff, but we found it takes quite a bit of gold to turn around and actually post a legendary or a precursor on the trading post. And then you run into the problem of undercutting, which may mean you need to pull it off after a week and attempt re-selling again. Some of the players in our guild are very poor, and this method makes it very difficult for them, especially if it's a precursor they don't want (i.e., Leaf of Kudzu).
So we prefer instead to just do a direct gold payout, and if someone wants to use that amount of gold to buy a precursor or a Mystic Forge Conduit, all the more power to them. We also make a point to include second and third place prizes, as that heightens a player's chances of winning. So that sometimes results in first place not being so large , but more guildies walk away happy (50%/30%/20% split).
Edited by Phineas Poe, 07 February 2014 - 02:44 PM.