As I said before, it leaves you vulnerable - you give a legitimate, active email address. The people running this won't contact you, but in an era of information, they'll sell their list of active emails to an internet marketer who is skilled at getting past your email filters and hitting your inbox. Information is power.
In this case, they've sworn that won't happen...
Yet what guarantee is there?
Well, anyone interested can create their own guarantee by maintaining a set of "disposable" email addresses. If any particular disposable address becomes a problem, you simply turn it off.
Granted, it's a matter of balancing the risks with the possibility of reward.
BTW, having now written about this obviously successful viral campaign, I am wondering how in the world I might adapt some similar word of mouth and exponential principles to sell more of my colloidal silver generators. I truly believe that every family on the planet needs one in their medicine cabinet, and yet I don't know how to propagate that idea...
You need a savvy internet marketer - I saw a Youtube vid the other day explaining the virtues of several nutrients and then at the end the presenter casually mentioned a product of his that contained all the nutrients in just the right amounts - sneaky and effective - Mind you, you'd have to reveal your face, lol. O, the price of loss of privacy - it must vex Oprah :)
No, not the face! :O
LOL...