Buddy Fan Club member
FS's have a need to balance regular goods production across the entire group. They recruit new members looking for goods they are low in. If they recruit for players boosted in Gems, they are not looking for that member to make gems to trade with marble members, they're looking for them to trade those gems for dust and elixir. Most FS's will allow cross trades when pre-arranged for specific member needs. Allowing cross trades on a regular basis makes it much harder to balance goods in the FS.There are many reasons for and against cross-trades, some are even valid but I have yet to hear of a single logical reason that justifies making rules against it.