The following will gain the characters wealth, but they do not count for XP purposes:
Coins looted from bodies outside adventure locations
Rewards
Selling equipment stripped from foes
Selling magical items that have been used by a player character or retainer
Tax income
Theft of wealth from mundane merchants, rulers and citizens
Trade, commerce and other business activity (including selling of mundane items stripped from foes)
The following treasures do count towards XP purposes:
Taken from the Lamentations of the Flame Princess ruleset, as shown here..