mediatic enigmatic

Why do channels Antena 3, Neox and Nova, which have totally different content and audience, share media scheduling and buys? Si alguien sabe el porqué, por favor explicádmelo porque no tiene ningún sentido en mi cabeza...

Let me explain, the three channels seem to be synchronized, so not only they get commercial interruptions at the same time they also get THE SAME ADS. So a financial services spot is running simultaneously in three channels where people are watching:
the 9 o´clock news, American Dad and a south american soap... ! The scheduling and space buy is done around Antena 3´s programming, the principal channel of the group, but is a total missed hit with the other two.

This does not make any sense to me and represents everything that is wrong with the old advertising model: interruptive, non relevant, non effective... a total waste of money and a bad name for the business.

Telecinco is not following this model with Factoria de Ficción, so I wonder about Antena 3´s motives (if any... could it be poor logistics and mere laziness?). It just seems such an amateur opportunity miss for the group...