Read this:
http://www.nissan4x4.co.za/forum/forum_posts.asp?TID=1644
Also, here is another thread that initially started this debate about 3-4 years ago:
Turboflo - Saves fuel increases power?? does it work? A way more intellectual debate than this one, I might add.
Now, I have decided to post in this thread for fear of necro-ing an entire thread of nearly 4 years old, but I would much rather be posting in the one above as they seemed to actually be having a debate.
All other questions aside. If you haven't tried it, how can you debunk it?
Bill Hicks had a nice saying, if you haven't actually "studied" something then stop your internal dialogue, which is occurring right now and just... walk.. away.
What if people have tried it and it actually works?
One is proposed to try it for 3 months and without any problem one is allowed to return it and you will be refunded.

The other post spoke of increase in power, which tends to draw a lot of people. Manufactured cars are not fitted with this device as they are instead fitted with way better devices. That and companies actually have international suppliers which they stick to. This device is cheap and accessible to a majority of people. It is said that 10% of people experience no difference. Hmm, now I'm no mathematician , but I believe that this means 90% of cases do. If a device that saves me 5% consumption on petrol and only costs me R147.50, I would be more than willing to look into it. Supposed average power increase of 3 - 9kw aside.
Lastly: I doubt a bunch of people who have never tried something, over the span (corrected from "spam") of 1 month is enough to debunk absolutely anything.