As you know, Adriano, sometimes these are also "promotions". That is, the seller has a new product with little market recognition. He lowers the price substantially to attract first-time buyers with the hope that, after falling to the temptation of the low price, the customer will try the product, like it, and then become a repeat buyer of the product. Right?
And sometimes they are "price leaders". That is, a seller offers them at a very low price to entice customers to his store. Once there, the hope is the consumer will buy many other items at regular prices. In the US, this often happens with basics such as sugar, flour, milk, baby food, etc. People are lured to the store for the low price sugar, but they then buy beer, steak, vegetables, cold-cuts, etc.