As guilds are run by players than we must accept that some players will try to manipulate others for profit, however many guilds are run by players with good intentions. I'm a part of a community that does lottery, and they are transparent about taking a small portion of the money for use in guild activities ( food and banners, etc.). For years they have consistently done as stated with each lottery. That, I believe, is a great way to do lottery. Alternatively I've seen another guild, mainly the leader, use lottery for personal profit. For example that player waited until after funds were received to claim that some money would be taken to benefit the guild. Shortly after the lottery the player was seen sporting new expensive skins that were not present before, while it was a friend of the player that won. No additional money or items were added to the guild bank as well. So for short, some guilds and players will do it for fun and to benefit the guild, while others do scam. If you suspect a scam, do report the player.