Comp policies vary from place to place,
but by playing $10 a hand or higher at most places and turning in the player's card to pitboss you will get rated and receive offers in the mail, often with discounts for rooms and restaurants. And they will often give you a comp for the coffee shop restaurant for a free meal after a couple hours of play if you just ask. Length of play and average bet are what they are looking at most often (your total "action"). Instead of getting your room free you might get it at a lower rate (often called casino rate) if your action was good but not great. You can speak with a casino host to see what action is needed to qualify for certain comps, that's their job. Just call the 800 number for the hotel and ask for a casino host, or table host. I've heard that the nicer Strip hotels typically want $25 per hand for 4 hours to get rooms comped.
Of course, turning in a player's card to get rated is asking the pitboss to watch your play so he can write down on the rating slip your activity. Many players believe this is not so good if you are a counter, increases your chance of being caught. All depends on your cover and bet level. Many places don't get too concerned with redchip play unless it gets really outrageous. Like I said, it really varies from place to place. The smaller places will get interested in redchip play if you start increasing the bet quickly, like tripling the bet when count goes more positive. Don't get too greedy and most place will tolerate the light action. Many players believe in not overstaying if you've won pretty good, but it is hard to leave a winning situation.