The reward mechanism
For a very full analysis of TVI see here. It includes details of the special introductory rewards you allegedly receive, but in fact you have to pay "processing fees and taxes" before you see any of them.
Others have commented that the pyramid mechanism itself is flawed and success unachievable.
The stupid vouchers
Yes, the vouchers really are stupid. To begin with they're worthless. Instead of spending serious money joining to get them why not buy similar vouchers much more cheaply?
It's also alleged that their membership list that scrolls on the right side of their web site is static, it never changes. This does seem to be the case.
TVI distributors have claimed that companies Virgin Atlantic, Lufthansa, Avis and Marriott were their "partners". This is simply a lie. Apparently Lufthansa and Avis sued TVI Express to stop them saying this.
Where are they?
TVI give their address in the UK as
"Lakeside House, 1 Furzeground Way, Stockley Park, Heathrow UB11 1BD"Heathrow is NOT in the UB11 postcode, which refers to Uxbridge. Heathrow is in the TW6 postcode area.
Previously they claimed to be based in an office in central London, only for it to be discovered that they weren't know at the address they gave.
They now claim to be based in an office in Cyprus but the same thing has happened again. There are reports that the address they give (Louki Akrita 14, Agiazoni, P.C. 3030, Limassol, Cyprus) is also shared with other companies.
Their UK phone number only goes through to an automated answering service, that says, when I last called, that I would be answered after 46 minutes.
They're under suspicion