A patent on a drug is somewhere in the nieghborhood of 20 years, hence the eventuality of a drug becoming available as a generic after so many years. I think what IGT probably has, is a trademark on the name silver strike. A trademark would be forever, unless sold or authorized to another entity. Another manufacturer could come out with something similar, but is there really enough of a market for it to be viable? In todays market, probably not. My personal opinion is that the $10 strike will be going away in the next few years as silver prices climb into the $20 Ounce range. I think you will see the $40 strike and the $1 machine become the normal for the program. Remember that Mandalay bay, The wynn, and Fremont have joined or rejoined the program within the last year, so there is Hope...