I'm not sure if you guys have this in your country, but in china we have this kinda ads that sell products (like medicine, watches, phones etc.) and they usually last for around 30mins and the products sold are not genuine. Old people always get tricked and buy those products through tv.

I don't know how to call this kinda ads.

I remember I've seen this expression somewhere before but I forgot....but I am sure the expression I've seen is not "Comerecial ads"