The traditional definition of an alliance has been the following: the pooling of resources and effort across multiple entities with the objective to achieve a competitive advantage in the marketplace. However, the ability of an alliance goes much beyond that. It is to do more with the the creation and the integration of new competencies out of the already existing stocks of prior competencies held by the organizations in question.
You could forge an alliance for a variety of reasons such as for marketing, R&D, technology. design and more popularly to create distribution channels. If one looks purely at brands and marketing, forging alliances have become critical because of changing trends. There are technological changes taking place at a rapid place with increasing globalization and constantly evolving consumer needs. In today's era of globalization, partnership with local firms to distribute and sell products under the local brand name achieves gaining a foothold in the market. In the case of evolving consumer needs, an important part of marketing then becomes identifying new consumer trends and the creation of products. Partnering therefore can not only reduce time to market but also make up for the lack of innovation focus within the company.
The most commonly cited example on alliances in classroom and various case studies is that between Microsoft, Intel IBM and Apple. When the PC industry began, competition existed between Apple and the IBM-Microsoft standard. IBM created and set out an open architecture standard that allowed any other computer manufacturer to build a clone of the IBM 'PC' itself and other software manufactures to deploy software to the IBM platform. This marginalized the Macintosh platform completely and the IBM PC became the de-facto standard. However, IBM and Microsoft fell into a dispute on operating system adoption where IBM was more interested in pushing OS/2 while Microsoft wanted to launch Windows. Microsoft then formed an alliance with Intel and launched Windows. Other PC manufacturers adopted this making Wintel the dominant standard thereby marginalizing IBM completely. IBM's open standard actually then worked against IBM's favor. IBM then went into an agreement with Apple to develop its new line of chip architectural design. Eventually, Apple realized that IBM support for it wasn't as good as they would have like it to be and adopted an Intel standard. The eventual implications of this are actually yet to be seen. It may be that the Mactel standards will be more aggressively pushed out by Intel in an attempt to marginalize the Wintel standard!
Alliances are about increasing the size of the pie rather than increasing one's share in the existing pie itself but they are not without challenges. What gets in the way more often than usual in establishing successful partnerships is to do with overcoming the 'proprietary mindset'. Partnerships require one to be willing to give something in order to get something and that requires a more 'collaborative mindset' than anything else. Also over 50% of all alliances have been failures. However, the average Fortune 100 company has over 60 alliances and given that these are Fortune 500 companies that we speak of, they must be doing something right.