Jim, I have no first-hand knowledge of the product, but I can say with a pretty high degree of certainty that it's more than likely a scam. There is NO way you can stimulate your penis to grow by chemical means - it's not physically possible (and by grow, I mean increasing actual size, not getting an erection - we all know that ED drugs have been proven to work pretty well). The only proven method of penis enlargement is through a risky surgery where a surgeon severs the suspensory ligament that holds your penis back into your body. While you MIGHT gain anywhere from 1/2 to three inches, guess what? You're penis, while erect, hangs down! Theres nothing there holding it up anymore. So, not a very sound option, and the risks of complications or deformity are pretty high.
If this tells you anything, the creator of Enzyte (remember smiling Bob? Yeah, the guy behind those annoying commericals) just got sentanced to 25 years in prison for defrauding millions of american men. Stay far away, it's 99.9% probably that they're just out to get your money. Hope that helps.