I would have to say word of mouth from someone that I know personally. A personal friend would have no reason to lie, There more trust worthy. TV products are all about marketing and the people who sell these products are experts in marketing, but Marketing doesn't mean good quality.
Actually, the more you sell to me, the more I hate what you're selling lol. They would pretty much just have to hold up the product and say "look" to get me to even think about looking it up myself and deciding from there. I detest commercials and infomercials and ads of any kind though.. I'm getting worse the older I get lol. Do NOT try to sell to me. It's why I don't do TV anymore and only go to a brick and mortar if absolutely necessary.