Harrah's [casinos] patrons can apply for a Total Rewards loyalty card and receive points toward anything from a hotel stay to catalog gifts; the more they gamble, the better the perks become. Each cardholder is assigned a "customer value" based on the theoretical revenue they will generate. Customers with higher values get quicker responses from Harrah's phone systems. When a gambler dials Harrah's toll-free reservation line, the computer bounces the number off its database and places the caller in the appropriate service queue.

The operator who picks up the phone is trained not to let on that the caller has been recognized. "That would be too creepy," says Rich Mirman, Harrah's senior vice president in charge of development, and a trained mathematician and economist...

Unlike rivals such as MGM Mirage, Harrah's tries hard to keep less profitable nongambling customers out of its hotels by calculating their customer value and making them pay through the nose. In October, a room at the aging Harrah's Las Vegas was quoted to a caller at a nightly rate of $199, only $14 cheaper than a super-luxury room at Bellagio.

A frequent gambler could be charged anything from nothing to $199 at the Harrah's casino, the company says. The price is based on a complex mathematical formula that takes into account how long the customer typically stays and what games he or she plays, among other details.