Club membership does not offer enough benefits. Here's a suggestion: A market to trade item, but only for players who currently have the club membership. They can trade items with other players who also have the club membership. Every member can trade only one item in every 24-hour time period. It is strictly an item-for-item trade. No item-for-pizza trade. No item-for-gold trade. No pizza-for-item trade. And an item must be traded for for another item of somewhat "equivalent" value. This extra benefit should entice players into joining the membership once in a while when they have items they want to trade or acquire.
