1. Revenue synergy 收入的协同效应：收购后，总收入更高，Equity 回报率更高，或者维持一个长期的增长。
2. Revenue synergy exists when the acquisition of the target company will result in higher revenues for the acquiring company, higher return on equity or a longer period of growth. Revenue synergies arise from:
a) Increased market power 提高市场上的话语权/占有率
b) Marketing synergies 市场效应
c) Strategic synergies 战略效应
3. Cost synergy 成本协同效应：规模效应导致了成本节约。经营规模的扩大， 会让边际成本降低，利润率更好。这种规模效应应常常是可持续的。
4. A cost synergy results primarily from the existence of economies of scale. As the level of operation increases, the marginal cost falls and this will be manifested in greater operating margins for the combined entity. The resulting costs from economies of scale are normally estimated to be substantial.
5. Financial synergy 财务协同效应：一家公司有盈余现金，另一家公司有好项目但缺乏资金，则这种合并可以创造价值。一家公司赚钱交很多税，一家公司亏钱不能享受税收减免政策，这种合作也可以建立税收上的好处。一家公司信用评级很好，另一家公司则没有融资能力，这种合并可以提升公司的举债能力，创造价值。多样化是一种可以提升融资能力，提升公司价值的方式。
1） cash slack 现金松弛：When a firm with significant excess cash acquires a firm, with great projects but insufficient capital, the combination can create value.
2） Tax benefits 税收效益： The tax paid by two firms combined together may be lower than the taxes paid by them as individual firms. If one of the firms has tax deductions that it cannot use because it is losing money, while the other firm has income on which it pays significant taxes, the combining of the two firms can lead to tax benefits that can be shared by the two firms
3） Debt capacity 举债能力：By combing two firms, each of which has little or no capacity to carry debt, it is possible to create a firm that may have the capacity to borrow money and create value. Diversification will lead to an increase in debt capacity and an increase in the value of the firm.
