Is Zicam legit?

I hardly ever get sick. It is rare for me to get sick. But occasionally, when Global Warming kicks in, and it suddenly gets cold, and I also come into contact with others on a subway or something, I will get the early symptoms of the upper respiratory infection that people call the common cold. Years ago, it was about a seven day ordeal of congestion, coughing and generally feeling like shit.

Then, I discovered Zicam. First time I get the symptoms, I take that stuff, and the worst thing that happens, I feel sort of crappy for two days, no congestion, maybe a ten hour cough and then done.

I think it works. Or not. What do you say?