I think that some lucky viewers get the TSV's sent to then a few weeks before they are launched to the general public. I have heared several T callers reviewing that days TSV, they ALWAY'S love it,its always just what they needed/wanted and now they couldn't live with out it.
How these lucky people get chosen I don't know, but I for one wouldn't like to be in the hot seat gushing over some c**py TSV.