An interesting piece from Wiesbaden:

"It is an unwritten rule that guests donate 1/35 of every payout to a so-called "Staff Kitty." Please note that this is not so that the croupiers receive extra tips; it is the only form of remuneration they receive. So, if you pay the corresponding percentage to the Kitty, we would like to say a big "Thank You" on behalf of our staff."

I usually toke my wager on every straight up/split win, and I always take care of slot folks, cage and any cocktail server who crosses by path in a professional manner during my casino visits.

JB