Pete, most states require surveillance to keep tapes 7 days. Most casinos are on a 2 week rotation. That means a tape will be used about 26 times a year and most are replaced yearly. A lot of casinos have put in digital systems. Retreival times vary, some things are on the system for several weeks. Some Surveillance Directors don't like the digital systems ams will not change. Tapes never hit the dumpster unless they are completely destroyed, methods vary, fire, sledgehammer, etc. Hope this answers your question. Regards, Jim