Until you provide us with an excerpt from contracts between hotels and supplier of bibles which explicitly mandates hotels to give away those bibles free of charge to their customers,
I doubt your going to get a contract. The bibles are supplied by Gideons. And yes, they actively encourage hotel staff to take bibles and some of them even pray for it to happen. The whole concept behind it is the distribution of the bible to as many people as possible.
In a world virtually awash with often in-your-face religious groups intent on showing the weary the way, Gideons stand out for being the only ones sung about by The Beatles who still somehow remain divinely unsung.
Relevent excerpt including Gideon International spokesman Woody Murray:
They are spiritual staples of nearly every hotel room and the only item guests are invited to steal.
“We don’t mind that at all,” said Murray. “Our statistics show one-quarter of all travelers will read the Bible in the hotel rooms and each Bible has the potential to reach 2,300 people over its six-year life expectancy.”
So Bible theft isn’t a sin?
“Not at all,” Murray said. “We often get notes in the mail with a contribution from someone saying, ‘Sorry, I took the Bible, but it saved my life.’ Take the Bible, not the towels.”
They'll be replaced. Take the Greenbrier, a luxury resort in White Sulphur Springs, W.Va. "The Greenbrier has Gideon Bibles in every room and keeps a stack handy to replace the 25 to 50 each year that are removed by guests," said resort spokesperson Lynn Swann.