This is a great question. One of the recent developments in the business world is to create strategic alliances and network structures. The most obvious reason for this is due to globalization. With modern technology the world is becoming a smaller place. And people are seeing the benefits of working together to streamline all aspects of business.
When it comes to alliances, the benefits are clear. Not all companies excel in all areas. For this reason, it behooves companies to work with others and create partnerships. In this way, there will be a symbiotic relationship; both companies can benefit. Most recently, Samsung and Apple created a partnership to create the new ipad. Samsung supplies the screens and Apple the hardware. Both companies will benefit greatly.
When it comes to networks, you hit upon a very important point. Strategist of network theory (usually in computer science) have pointed out that if a person adds on node in the network, everything can be exponentially more effective. Companies has taken this insight and applied it to business. In light of this, companies seek to create networks. In fact, this idea of networking is common parlance now and people are much more open to working with other on many levels.
In light of all of this, companies are creating an atmosphere where the organizational DNA is able to network and form strategic partnership.