The accepted mode of getting otherwise unobtainable information is to go visit the cranky old hermit living in the mountains. It's just the sensible thing to do. So, naturally, everyone takes their monthly excursion to the hermit's hovel to consult him on everything, from lock-jaw to lovesickness, necromancers to nasal viruses.
Now, if everyone's always visiting the poor old hermit, there's going to be an enormous queue... "Wellcome to the Hermitt's Hovele, Please Take Ye a Number and Have Ye a Seate" reads the sign outside the packed dwelling.
Imagine the poor hermit, having retreated into the mountains to escape this precise situation...
Mages/ wizards and such use cards (playing cards or tarot cards) as training tools. The patterns created by certain layouts of cards are mnemonic devices to teach key elemental associations and paths. With such interesting names as the Tree of Life, Phoenix's tail, Rythm of Heart, and Balance of the sphere, there pattern represent the matrices used by magic users to focus and present power. Spell processes can be represented by a sequence of cards.
So mages will often be seen handing around hands of cards.
Wizards will have a deck of cards with them. Since cards were used to train wizards in legerdemain, Since they have cards with them, they frequently know how to use them. Guild magic users often have a knack for fancy shuffles, palming cards, and a variety of card tricks and games.