Some suggestions
I advertise on matchbooks, yellow pages, giveaway postcards, 9 different business cards, Internet website. Posting on AZbilliards and several different sites. I also have a MySpace page with discounts for "friends" listed on our page. I also advertise on Craigslist under the small business section as well other areas when applicable. I will post under sporting goods when I am selling a pool table or cue stick sometimes. Poolrooms.com and other listing sites. Advertise on Entertainment book and their website. The generation of under 25 does MOST of their research for entertainment ONLINE. Not to concentrate on that segment of the market is slitting your own throat to the next generation of pool players. Concentrate on Students, highschool and college. Putting up flyers at local schools offering student rates or coupons you print yourself.
http://www.cueandcushion.com/specials/webspec1.htm If you are not spending at least 3-4 hours a week online promoting yourself. You are letting business slip away. I also advertise with local restaurants with exchange coupons. We give away coupons to their restaurant..they give away pool coupons. We give discounts to leagues for dart supplies in exchange for mailing list names and customers. There are a lot of good books out there I recommend.
I sell tee shirts with our web address and specials listed on them at cost. I then give price specials to people that wear them. This way the customer gets a shirt cheap and you get advertising around town when they wear them out to other places. This has been VERY successful for us.
Jay Conrad Levinson has several books on marketing. Some of the points are repeated in following books but buy them used on Amazon and the information is really worthwhile. Some of it common sense some will give you "light bulb" moments. The Guerrilla Marketing series of books is a keeper. Make all your employees read them too.
Everytime you buy a product online. Review it and sign it with your name and web site address. You have to get in the habit of advertising every single chance you get. Once you do it becomes second nature and new customers are always trickling in.
Just some ramblings off the top of my head.
Have contests in your pool room. Free pool for a month to anyone that designs a tee shirt. The person will most likely get tired of practicing alone. They will invite new friends to play that month exposing your room to new blood.
You can have other contests once a month with free pool as the grand prize.
Always give free pool to people on their birthday. People rarely celebrate alone and bring friends in with them.