This article does not specifically talk about media companies, although it does mention them in the context of the current waves of spin offs and having conglomerates split up after not realizing the promised synergies before the mergers.  Indeed, there seems to be a penalty for conglomerates right now, such that the sum of the parts is probably worth more.  The idea behind many mergers was that the companies together would be more valuable than their individual assets added together, although it has since been proven that that is not the case.  According to Media Economics, Theory and Practice, 75% of all mergers and acquisitions fail to deliver on promises made to investors.